PuTTY Known Bugs and Wish List

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This is the list of bugs that need fixing, and features that want adding, to PuTTY. The ‘pending’ list represents things that have not been done to the current development code; items marked as ‘fixed’ may not yet be in the latest release.

If you do not see a feature here, it's also worth checking the Changes page before mailing us to ask for the feature; it might already have been added.

There are other sites tracking bugs and feature requests in downstream packages of the Unix port, some of which undoubtedly apply to our code: Debian, Launchpad (us, Ubuntu), NetBSD.

Search the wishlist:

WWW www.chiark.greenend.org.uk

Recently fixed

These are items we believe we have already addressed. See also the Changes page.

Fixed in current snapshots

• Bugs (and semi-bugs)
  • openssh-ed25519-corrupt-private-key: PuTTYgen mis-writes OpenSSH private key format for some Ed25519 keys
• Wishes
  • curve448: Support Curve448 key exchange method
  • ed448: Support Ed448 user and host keys
  • pageant-named-pipe: Replace Windows Pageant's IPC with named pipes
  • pscp-port-0: On a clean machine, PSCP tries to connect to port 0

Fixed in release 0.74

• Security vulnerabilities
  • vuln-agent-keylist-used-after-free: Key list from agent used after free if server rejects signature after PK_OK
  • vuln-dynamic-hostkey-info-leak: Dynamic host key policy leaks information about known host keys

Fixed in release 0.73

• Security vulnerabilities
  • vuln-bracketed-paste-data-outside-brackets: Vulnerability: bracketed paste data appears outside bracket sequences
  • vuln-win-exclusiveaddruse: Vulnerability: Windows local forwarded ports rebindable by another application
• Bugs (and semi-bugs)
  • ssh1-disconnect-use-after-free: Use-after-free bug when processing SSH-1 disconnect message
  • win-plink-downstream-startup-crash: Windows Plink crashes on startup if it's a connection-sharing downstream

Fixed in release 0.72

• Security vulnerabilities
  • vuln-ssh1-buffer-length-underflow: Vulnerability: integer underflow parsing SSH-1 packet length
  • vuln-ssh1-short-rsa-keys: Vulnerability: buffer overflow in SSH-1 if server sends two tiny RSA keys
  • vuln-win-pageant-client-missing-length-check: Vulnerability: Windows Pageant client code does not check response length field
• Bugs (and semi-bugs)
  • connshare-overlarge-packets: Pasting very long line into connection-sharing downstream can close it
  • english-keypad: Numeric keypad always uses English key bindings (e.g., decimal point) on Windows
  • gssapi-kfw-crash: GSSAPI with MIT Kerberos-for-Windows or third-party DLL crashes
  • kbdint-instruction-ignored-2: SSH keyboard-interactive instructions to user are not displayed
  • pageant-ecdsa-assert-fail: Adding ECDSA key to running Pageant causes assertion failure
  • portfwd-edit-crash: Removing local tunnel can cause crash
  • scp-newline: PSCP in SCP mode can try to write filenames containing newlines
  • scp-preserve: PSCP in SCP mode messes up file download with '-p' option
  • trust-sigil-restart: Terminal window 'trust sigils' absent after Restart Session
  • trust-sigil-ssh1-rlogin: Terminal window 'trust sigils' never turned off in SSH-1 or Rlogin
  • puttygen-keys-one-bit-short: RSA keys generated by PuTTYgen could be one bit too short

Fixed in release 0.71

• Security vulnerabilities
  • vuln-auth-prompt-spoofing: Authentication prompts can be spoofed by a malicious server
  • vuln-chm-hijack: Potential malicious code execution via CHM hijacking
  • vuln-fd-set-overflow: Buffer overflow in Unix PuTTY tools if server opens too many port forwardings
  • vuln-rng-reuse: Cryptographic random numbers can occasionally be reused
  • vuln-rsa-kex-integer-overflow: Integer overflow due to missing key-size check in RSA key exchange code
  • vuln-terminal-dos-combining-chars: DoS if many Unicode combining characters are written to the terminal
  • vuln-terminal-dos-combining-chars-double-width-gtk: DoS by terminal output involving combining characters, double-width text, an odd number of terminal columns, and GTK
  • vuln-terminal-dos-one-column-cjk: DoS by terminal output if a CJK wide character is written to a 1-column-wide terminal
• Bugs (and semi-bugs)
  • pscp-unsanitised-server-output: PSCP should strip unprintable characters from SCP server output
  • side-channels: Rewrite crypto code to avoid cache/timing side channels
  • paste-filter-controls: Filter out control characters by default when pasting
• Wishes
  • arm-windows-build: Build for Windows on Arm
  • clipboard-generality: Revamp copy/paste UI and handle multiple clipboards
  • cpu-crypto-accel: Use CPU cryptographic acceleration instructions where available
  • gss-key-exchange: GSSAPI key exchange
  • ssh-server: Write an SSH server based on the PuTTY code, for testing purposes
  • pageant-rsa-sha2: Pageant support for SHA-256/512 RSA signatures, used by e.g. OpenSSH client
  • paste-semantics: Alternative semantics for copy and paste
  • puttygen-openssh-aes-ctr: Support OpenSSH 7.6+ aes256-ctr-encypted private keys
  • true-colour: Support for even more colours
  • utf8-plus-vt100: Simultaneous support for UTF-8 and enough ISO-2022 sequences for VT100 line drawing

Broken and fixed between release 0.70 and release 0.71

• vuln-dss-verify: Vulnerability: DSA signature check bypass (development code only)

Fixed in release 0.70

• Security vulnerabilities
  • vuln-indirect-dll-hijack-3: More potential malicious code execution via indirect DLL hijacking
• Bugs (and semi-bugs)
  • win-tounicodeex-bis: Regression in Windows Unicode keyboard handling
  • windows-printing-crash: Printing on Windows causes a crash

Fixed in release 0.69

• Security vulnerabilities
  • vuln-indirect-dll-hijack-2: Further potential malicious code execution via indirect DLL hijacking
• Bugs (and semi-bugs)
  • mit-kerberos-dll-trouble: MIT Kerberos GSSAPI support broken (can't load its DLLs)
  • dup-sessions-dont-close: On Windows, parent session doesn't close until child does

Fixed in release 0.68

• Security vulnerabilities
  • vuln-agent-fwd-overflow: Vulnerability: integer overflow permits memory overwrite by forwarded ssh-agent connections
  • vuln-indirect-dll-hijack: Potential malicious code execution via indirect DLL hijacking
• Bugs (and semi-bugs)
  • deprecate-dh-group1: Deprecate key exchange method diffie-hellman-group1-sha1
  • needs-removeable-media: Starting a session fails with "There is no disk in the drive"
  • win-process-acl-finesse: Restrictive Windows process ACL causes trouble with screen readers, etc
  • sftp-close-status: Psftp doesn't check return value for SSH2_FXP_CLOSE request
• Wishes
  • chacha20-poly1305: Support for ChaCha20-Poly1305 authenticated encryption
  • curve25519: Support for Curve25519 key exchange
  • ecdsa: Support for ECDSA keys in PuTTY and PuTTYgen
  • ed25519: Support for Ed25519 user and host keys
  • hostkey-policy: Enhanced flexibility in SSH host key selection policy
  • hostkey-prefer-cached: PuTTY should prefer host-key types it already has cached
  • no-ssh1-fallback: Remove fallbacks between SSH-2 and SSH-1
  • port-unix-gtk3: Port to Gtk+-3 toolkit on Unix
  • win64-binaries: Provide 64-bit Windows executables
  • encrypt-then-mac: Add support for OpenSSH encrypt-then-MAC scheme

Broken and fixed between release 0.67 and release 0.68

• vuln-ecdsa-newkey: Vulnerability: use of uninitialised pointer loading ECDSA keys

Fixed in release 0.67

• Security vulnerabilities
  • vuln-pscp-sink-sscanf: Vulnerability: old-style scp downloads may allow remote code execution
• Bugs (and semi-bugs)
  • win-silent-uninstall: Silent uninstall not possible on Windows
• Wishes
  • installer-addpath: Add path to PuTTY programs to PATH in Windows installer
  • msi-installer: MSI installer for PuTTY on Windows

Fixed in release 0.66

• Security vulnerabilities
  • vuln-ech-overflow: Vulnerability: integer overflow and buffer underrun in terminal emulator's ECH handling
• Bugs (and semi-bugs)
  • win10-jumplists: Pinned/Recent Sessions UI feature doesn't work on Windows 10

Fixed in release 0.65

• Bugs (and semi-bugs)
  • spew-lockup-2: Remote terminal spew can freeze terminal and lock out local GUI (again)
  • vista-update-breaks-config: Windows Vista update KB3057839 breaks PuTTY configuration dialog
  • psftp-batch-exit-code: PSFTP failures don't always produce failure exit code
• Wishes
  • rfc4419: Support the RFC 4419 revision to Diffie-Hellman group exchange

Fixed in release 0.64

• Security vulnerabilities
  • private-key-not-wiped-2: Failure to scrub private keys from memory after use
• Bugs (and semi-bugs)
  • bold-font-default: Default bold text display accidentally changed, rendering 'bold black' invisible
  • diffie-hellman-range-check: Missing range check in Diffie-Hellman key exchange
  • ssh-close-vs-request: Trouble when SSH channel closed with outstanding requests
  • dynamic-tunnel-session: Cannot use dynamic port-forwarding with specific IP protocol in saved session
  • hostkey-rekey: If the host key isn't saved, rekeys cause another warning
  • ipv6-literals: Better handling of literal IPv6 addresses
  • pscp-unexpected-eof: "Received unexpected end-of-file from server" with PSCP
• Wishes
  • ssh2-generality: Support for SSH-2: zero, or more than one, terminal per session
  • ssh2-only-default: Stop trying SSH-1 by default
  • cmdline-hostkey: Option to specify expected host key(s) on the command line
  • resize-no-truncate: Reducing window width shouldn't lose information

Fixed in release 0.63

• Security vulnerabilities
  • private-key-not-wiped: Private keys left in memory after being used by PuTTY tools
  • vuln-bignum-division-by-zero: Vulnerability: non-coprime values in DSA signatures can cause buffer overflow in modular inverse
  • vuln-modmul: Vulnerability: buffer underrun in modmul can corrupt the heap
  • vuln-signature-stringlen: Vulnerability: negative string length in public-key signatures can cause integer overflow and overwrite all of memory
• Bugs (and semi-bugs)
  • half-closed: PuTTY doesn't permit half-closed connections
  • kexinit-unimplemented: SSH_MSG_UNIMPLEMENTED in response to SSH_MSG_KEXINIT is ignored
  • portfwd-space: Arbitrary restriction on number of forwarded ports
  • multi-key: Support for Multi_Key in GTK port
  • unix-dead-keys: Dead keys don't work on Unix
  • unix-sigpipe: Unix Plink dies with SIGPIPE when a forwarded port closes
  • uxplink-winsize-override: Unix Plink inappropriately uses configured window size
  • win-tounicodeex: Unicode character input on Windows (for Romanian, etc)
• Wishes
  • config-struct: Remove fixed-length buffers in configuration structure
  • utf8-default: Make UTF-8 the default line character set
  • bold-font-colour: Ability to change font *and* change colour for bold text

Fixed in release 0.62

• Security vulnerabilities
  • password-not-wiped: Passwords left in memory using SSH keyboard-interactive auth
• Bugs (and semi-bugs)
  • gssapi-access-denied: Spurious "Access denied" printed in the PuTTY window after GSSAPI failure
  • pageant-backwards-compatibility: 0.61-style Pageant does not work with 0.60-style PuTTY
  • pscp-nonstd-port-number: PSCP and PSFTP do not honour nonstandard port numbers in saved sessions
  • puttytel-gssapi-assertion: PuTTYtel fails an assertion when saving a session
  • underlining-shifted-right: Underlining on text displayed to the right of where it should be
  • vt100-line-drawing-oprs: VT100 vertically offset horizontal line characters mis-displayed on Windows

Fixed in release 0.61

• Bugs (and semi-bugs)
  • cygwin-clobbers-pageant: Plink (etc) run under Cygwin cannot talk to Pageant
  • flow-control: Be cleverer with SSH-2 flow control to improve bulk throughput
  • flow-control-filexfer: Be less clever with SSH-2 flow control in PSFTP and PSCP
  • kbdint-instruction-ignored: SSH keyboard-interactive instructions to user can be discarded
  • plink-hostname: Plink using wrong hostname when one is saved in Default Settings
  • portfwd-addr-family: Unix listening sockets (e.g., tunnels) are IPv6-only by default
  • pscp-psftp-fail-hang: PSCP/PSFTP hang on exit in some failure cases
  • rdesktop-paste-hang: Paste from tunneled Remote Desktop session into PuTTY causes hang
  • rsa-import-primeorder: PuTTYgen shouldn't insist that p > q in imported OpenSSH RSA private keys
  • ssh2-cbc-pktlen-weakness: In CBC modes, decrypting the packet length can leak information
  • unix-stderr-opost: When stdout and stderr are ttys, plink's messages stair-step
  • cmdline-nc-garbage: -nc on the command line mangles the host name
  • local-proxy-telnet: Data received from local proxy commands tagged as TCP Urgent (breaks telnet)
  • pscp-start-hang: PSCP can throw away the start of an SCP session and hang waiting for it
  • ssh1-no-password: PuTTY tries password authentication even if the server says not to.
  • ssh2-window-overrun: PuTTY is confused by servers that don't respect its window
  • unclean-close-hang: Unclean close on Vista/Windows 7 leads to CPU-bound hang
  • unix-connreset-spin: Unix PuTTY spins in tight loop after abnormal exit
  • unix-lp64: PuTTY is broken on LP64 Unix systems
  • unix-plink-stdout-nonblock: Unix Plink should set O_NONBLOCK on stdout and stderr
  • win-serial-hang: Serial backend on Windows hangs on simultaneous input/output
• Wishes
  • kerberos-gssapi: Support for GSSAPI (for Kerberos, GSI, etc)
  • port-unix-gtk2: Port to Gtk+-2 toolkit on Unix
  • puttygen-openssh-aes: Support OpenSSH AES-encrypted keys in PuTTYgen
  • windows-utf16: Support UTF-16 on Windows
  • x11-auth: Authenticate with local X servers
  • zlib-openssh: Support for "zlib@openssh.com"
  • cmdline-serial: Ability to specify a serial connection on the command-line
  • crhaslf: Add "Implicit LF with every CR" option
  • non-fixed-width-fonts: Support for non-monospaced fonts
  • ssh2-rsa-kex: Implement SSH-2 RSA key exchange
  • win7-jumplists: "Jump list" support in Windows 7

Broken and fixed between release 0.60 and release 0.61

• ssh2-bug-maxpkt: Servers send oversize packets, leading to garbled packet errors
• ssh2-rsa-kex-pref: RSA KEX ends up at the bottom of pref list on upgrade
• winadj-success: Bombing out with 'Received SSH_MSG_CHANNEL_SUCCESS for "winadj@putty.projects.tartarus.org"'

Fixed in release 0.60

• Bugs (and semi-bugs)
  • defaults-launchable: "Default Settings" can be launchable, leading to confusion
  • ssh2-romsshell-badpacket: PuTTY emits invalid SSH_MSG_IGNORE packets
  • win-com10: Make access to serial ports above COM9 easier on Windows
  • win-handle-double-free: Crashes on Windows with serial backend
  • win-plink-stdin-eof: Plink reports an error when it gets EOF from standard input
  • 256-colours-broken-gtk: Colours generated by 256-colour code are wrong on Unix
  • psftp-missing-subdirs: PSFTP "mput -r *" misses some items in subdirectories
• Wishes
  • break-key: Ctrl-Break to send break signal instead of ^C

Fixed in release 0.59

• Bugs (and semi-bugs)
  • drop-banner: PuTTY drops USERAUTH_BANNER when awaiting username input
  • ki-multiprompt-crash: Crash with SSH keyboard-interactive packet with multiple prompts
  • large-files: PSFTP and PSCP can't handle big files (> 2 GB, > 4 GB)
  • optimise-bignum: Enable bignum optimisation for Windows Visual C builds
  • spew-lockup: Remote terminal spew can freeze terminal and lock out local GUI
  • ssh1-bad-passphrase-crash: Entering wrong SSH-1 key passphrase causes PuTTY crash
  • ssh2-password-expiry: Support for SSH-2 password expiry mechanisms
  • vista-ipv6: IPv6 support doesn't work in Windows Vista
  • win-font-linking: Windows Unicode font linking broken
  • win-randseed-location: PuTTY's placement of PUTTY.RND is non-optimal on Windows
  • xp-wont-run: Fails to run on some versions of Windows XP
  • 256-colours-match-xterm: 256 colour mode does not match xterm's colours exactly
  • beepind-win2k: Clean up taskbar bell indication
  • gcc4-warnings: Compiling the Unix version with GCC4 generates warnings
  • ipv6-scoped-addr: On Windows, IPv6 scoped addresses don't work
  • large-clipboard-crash: Crashes with large clipboard operations containing lots of blank space
  • portfwd-invalid-origin: Some servers reject SSH-2 tunnels due to invalid originator IP address
  • psftp-hang: PSFTP hangs/consumes 100% CPU when launched from Explorer
  • pubkeyfile-and-pageant: Pageant + explicit keyfile gives non-optimal behaviour
  • puttygen-unix-perms: Unix puttygen can create world-readable private keys
  • raw-mouse-copy: Clipboard operations unreliable in mouse reporting mode
  • restart-reset-terminal: Reset terminal state when restarting session
  • ssh-bug-rekey2-notsaved: SSH-2 rekey bug-compatibility setting not saved
  • ssh1-fwd-trouble: Reports of SSH-1 trouble, particularly with port/X11 forwarding
  • unknown-cipher-hang: PuTTY hangs if a saved session's preferred cipher is unknown
  • virt-dim-menu-trouble: Window close button disabled with Virtual Dimension
  • win-askappend-multi: Logging dialog box duplicated, and can cause session to hang
  • win-canonical-hostname: Canonical hostname (in title bar) uses reverse lookup on Windows
  • wm-app: PuTTY should use WM_APP, not WM_USER
  • zero-rows-cols-crash: Setting rows and columns to zero causes crash
• Wishes
  • dh-gex-sha256: Implement "diffie-hellman-group-exchange-sha256"
  • proxy-command: Proxying through arbitrary command (e.g. another SSH session)
  • serial-backend: Back end that talks to a serial port instead of a network
  • ssh2-cbc-weakness: SSH-2 CBC weaknesses can be worked around
  • ssh2-cisco-pw-pad: Cisco SSH-2 servers can't handle over-padded packets
  • terminal-modes: Implement sending of full terminal modes in SSH
  • win-versioninfo: Add VERSIONINFO resource to Windows binaries
  • arcfour: The Arcfour cipher isn't supported
  • bypass-ssh2-userauth: Ability to bypass user authentication in SSH-2
  • font-quality: Ability to configure font quality (and support ClearType)
  • ssh2-ctr-modes: SSH-2 CTR cipher modes
  • term-clear-scrollback: Server-controlled clearing of the scrollback
  • unix-portability: Extra portability in the Unix port
  • win64: Support builds for 64-bit Windows

Fixed in release 0.58

• Bugs (and semi-bugs)
  • bidi: Bidirectional text support
  • disconnect: Better handling of the connection closing
  • font-overflow: Fonts that overflow their character cells cause problems
  • kbdint-failure: Keyboard-interactive authentication only permits one try
  • multiple-addresses: PuTTY mishandles machines with multiple addresses
  • portfwd-reconf: Reconfigurable port forwarding
  • ppk-longline-crash: Long lines in PPK files (e.g. long key comments) can cause crash
  • pterm-logtype-crash: pterm aborts if Default Settings has SSH packet logging enabled
  • ssh2-kex-data: Data transfer during SSH-2 KEX causes confusion
  • ssh2-kex-repeat: Ability to initiate SSH-2 key re-exchange
  • ext-data-at-start: "unexpected packet type 95" with VShell 2.1.5
  • kexinit-guess: first_kex_packet_follows is ignored
  • multi-changesettings-crash: Multiple Change Settings dialogues cause crash
  • pageant-dirhandle: Pageant keeps open handles on removeable media
  • plink-keepalives: Keepalives don't work in Plink
  • portfwd-at-start: "unexpected packet type 91" with tunnel open during connection setup
  • pterm-timer: pterm should use no CPU if it's not doing anything
  • sci-is-not-decid: PuTTY misinterprets SCI as DECID
  • ssh-remoteid-minusone: Remote channel numbers of 0xffffffff will confuse PuTTY
  • telnet-option-loop: PuTTY violates RFC-854 option-loop prevention
  • time_t-minus-one: time() returning (time_t)-1 is mishandled
  • unix-keepalives: Keepalives not yet implemented on Unix
  • unix-kex-packet: Unix: "expected key exchange reply packet from server" and crash
  • wcwidth-upgrade: Upgrade wcwidth() to Markus Kuhn's latest version
  • xdmauth-replay: PuTTY doesn't apply replay protection to XDM-AUTHORIZATION-1
• Wishes
  • compressed-scrollback: Compress scrollback contents to reduce memory usage
  • do-text-unicode: do_text() is mad in a Unicode world
  • ipv6-build: We should provide IPv6-enabled binaries.
  • save-mid-session: Saving session preferences after starting the session
  • ssh2-sequence-wrap: SSH-2 replay attacks should be avoided
  • unicode-combining: Support Unicode combining characters
  • unicode-more-planes: Support for Unicode above U+FFFF
  • 256-colours: Support for more colours
  • disable-colour: Features panel -- disable ANSI colour escape sequences
  • ipv6-patch-update: unfix.org has further IPv6 patches; integrate?
  • psftp-multi: Multiple file transfers (wildcards, recursion) in PSFTP
  • wcwidth-cjk: Checkbox to enable use of wcwidth_cjk()

Fixed in release 0.57

• Security vulnerabilities
  • vuln-sftp-readdir: Vulnerability: crafted SFTP FXP_READDIR reply may allow remote code execution
  • vuln-sftp-string: Vulnerability: crafted SFTP string may allow remote code execution
• Bugs (and semi-bugs)
  • ssh-remote-tunnel-crash: SSH remote tunneling may cause crash
  • x11-local-display-broken: X11 forwarding to implicitly specified local display broken

Fixed in release 0.56

• Security vulnerabilities
  • vuln-ssh2-debug: Vulnerability: crafted SSH2_MSG_DEBUG can cause remote code execution
• Bugs (and semi-bugs)
  • ampersat-in-username: Allow @ sign in username
  • log-flush: Flush session log file during session
• Wishes
  • mazovia: Support for Mazovia character set
  • socks5-chap: CHAP authentication support for SOCKS5
  • reuse-windows: Ability to re-use dead session windows
  • ssh-log-pw-blank: Blank known passwords by default in SSH packet log
  • ssh2-env-var: Support setting environment variables in SSH-2

Fixed in release 0.55

• Security vulnerabilities
  • vuln-modpow: Vulnerability: serious buffer management bug in modpow()
  • vuln-ssh1-kex: Vulnerability: buffer management bug in SSH-1 key exchange
• Bugs (and semi-bugs)
  • hard-hangs: PuTTY becomes unresponsive / unkillable on Win2000/XP
  • ntpd-slowdown: PuTTY causes ntpd to lose time
  • psftp-pscp-ignore-load: PSFTP and PSCP ignore the -load option
  • win-dead-keys: Trouble with dead keys on Windows
  • copyall-to-cursor: "Copy All to Clipboard" misses out screen contents after cursor
• Wishes
  • pscp-select-backend: Ability to explicitly select SCP/SFTP backend in PSCP
  • ssh-termspeed: Send terminal speeds in SSH
  • tcp-keepalives: Ability to enable TCP keepalives

Fixed in release 0.54

• Security vulnerabilities
  • vuln-passwd-memdump: Failure to scrub SSH-2 password from memory after use
  • vuln-window-title: Window title reports offer opportunities for mischief
• Bugs (and semi-bugs)
  • ppk-empty-comment: Trouble with empty PPK key comments
  • proxy-uninit-members: Proxy crash caused by uninitialised structure members
  • puttygen-zero-div: Occasional PuTTYgen division-by-zero errors
  • resize-scroll-effects: Resizing the window does the Wrong Thing to its contents
  • rsa-non8mult-verify-fail: RSA signature validation fails with non-8-bit-multiple keys
  • sftp-slow: PSFTP, and PSCP in SFTP mode, transfer files much slower than old-PSCP.
  • slow-startup-printer: Printer enumeration may cause slow startup
  • winnet-if2lo: PuTTY refuses connections to 127.0.0.1 from interface IP addresses
  • x11-proxy-crash: Proxy + SSH + X11 forwarding fails and/or crashes
  • cmdline-host-override: -load overrides a host name specified on the command line
  • deccolm-cls: DECCOLM should clear the screen
  • hostkey-prompt-type: Host key prompt doesn't state type of key
  • inactive-title: Minimising / restoring inactive windows loses (Inactive) in title
  • logging-save-default: Logging settings are not saved with Default Settings
  • msproxy-denied: Connections through MS Proxy Server (HTTP) are spuriously denied
  • portfwd-loopback-choice: Choice of loopback addresses for local port forwardings
  • pterm-windowid: pterm should set WINDOWID environment variable
  • resize-minimise: Resize after Alt-Space, N minimise doesn't work
  • ssh2-des-cbc-is-std: Cipher "des-cbc" is less non-standard than PuTTY claims
  • ssh2-keyderive-nonbug: SSH 2.0.13 apparently doesn't have key-derivation bug
  • ssh2.0.11-keyderive-nonbug: SSH 2.0.11 apparently doesn't have key-derivation bug
  • strange-winsock-msg: Strange WinSock messages cause failed assertion in tree234.c
  • telnet-binary: PuTTY doesn't support the BINARY option
  • telnet-resize-iac: PuTTY doesn't correctly encode 255x255 NAWS messages
  • vshell-no-bug-compat: Bug compatibility modes accidentally triggered for VShell.
  • x11-default-screen: PuTTY doesn't pass on the screen number in X11 forwarding
• Wishes
  • pc-speaker: Beep using the PC speaker
  • port-unix: Port to Unix
  • portfwd-dynamic: OpenSSH-style dynamic port forwarding
  • remove-statics: Remove static variables to allow multiple or sequential connections
  • ssh-default: Change PuTTY's default protocol from Telnet to SSH
  • vstudio-project: Visual Studio project files (.DSP/.DSW)
  • baltic-default-translation: Change default charset for Baltic Windows from Latin-4 to Latin-7
  • bce-default-change: Perhaps the default for BCE should change
  • context-menu: Context menu on Ctrl+right-click
  • control-slash: Ctrl+/ should send the same as Ctrl+_
  • ctrl-pgupdn: Ctrl-PgUp and Ctrl-PgDn to scroll by one line at a time.
  • default-colours: Be able to use the Windows default colour scheme
  • hostname-whitespace: Ignore whitespace in the Host Name box
  • icon-title-default-change: Turn on 'avoid ever using icon title' by default
  • keyfile-diagnostic: Better diagnostics on failure to load private key file
  • offer-to-reset: Allow immediate change of initial-terminal-state settings
  • proxy-lookup: Option to leave DNS lookup to proxies
  • resize-altscr: Resizing window has nasty effects on alternate screen
  • screen-clear: Screen clears should interact with scrollback differently
  • sftp-backend-diagnostic: Better diagnostics from file transfer backends
  • shift-backspace: Shift-Backspace should do the other of ^H and ^?
  • ssh2-default: Default to SSH-2 protocol instead of SSH-1

Fixed in release 0.53b

• Security vulnerabilities
  • vuln-sshredder: SSHredder test suite vulnerabilities (CERT CA-2002-36)
• Bugs (and semi-bugs)
  • pscp-cmdline-port-bug: -P option sometimes ignored by PSCP

Fixed in release 0.53

• Bugs (and semi-bugs)
  • nonexistent-channel: `nonexistent channel -1' crashes
  • portfwd-open-crash: Crashes with heavy open/close activity in port-forwarding
  • win98-wheel: Wheel mouse support broken under Win98
  • freebsd-4.6-ki-crash: SSH-2 keyboard-interactive crashes with FreeBSD 4.6-STABLE
  • long-usernames: Increase space allocated to auto-login username
  • pscp-memory-leak: PSCP ballooning on large files
  • ssh.com-userauth-refused: Breakage when compression enabled with ssh.com 3.2.0 server
• Wishes
  • command-line: Better command line options
  • proxy: Support for proxying of connections
  • key-formats: Support for OpenSSH and ssh.com SSH-2 private key formats
  • rsa-verify-failed: Occasional `Access denied' / `RSA_verify failed' (OpenSSH bug)
  • ssh2-only: Ability to prevent fallback to SSH-1
  • xp-shortcut: Trouble creating PuTTY shortcuts in WinXP

Broken and fixed between release 0.52 and release 0.53

• printer-list: Printer list not working properly

Fixed in release 0.52

• Bugs (and semi-bugs)
  • keymap-switch: Switching Windows keymaps is ignored
  • null-opaque-resize: Opaque resizes under NT cause trouble

Pending

These are bugs still to be fixed and features remaining to be implemented.

Bugs

These items are clearly actual problems and I want them fixed.

• portfwd-corrupt: Reports of port forwarding corruption
• pscp-size-change: PSCP assertion failure if remote source file changes size
• win-jumplist-trouble: Trouble with Windows 'jump lists' of recently used sessions since 0.68
• assert-fail-newsavelines: Failed assertion: count234(term->scrollback) <= newsavelines
• assert-line-not-null: Bombs out with line==NULL in terminal.c
• change-scrollback-altscr: Changing scrollback size when on alternate screen clears the screen
• ctrl-pgupdn-config: Ctrl-PgUp and Ctrl-PgDn scrolling should be configurable
• exit-codes: Provide more useful exit codes
• fatal-errors: Fatal error handling is patchy and flaky.
• fullscreen-taskbar: Switching to full-screen doesn't always hide taskbar
• gtk-xsun-badatom: GTk port gives BadAtom errors when talking to Xsun
• keyboard-problems: Problems with various keyboard layouts / input methods
• pageant-load-fail: Pageant -c continues even if key load fails
• pscp-recursion-dest-dir: PSCP recursive copy to a new directory tries to copy all files over that dir
• psftp-assert-lp64be: PSFTP doesn't work on big-endian 64-bit systems
• puttygen-accel-bogosity: Bogosity with PuTTYgen keyboard accelerators and menu bar
• resize: Resizing the window is still pretty flaky.
• rlogin-blocked: Cannot rlogin to host after uncleanly terminated connection
• short-rsa2-key-crash: Short RSA2 key causes PuTTY crash
• ssh-stuck-queue: SSH data can get stuck in a queue if session throttled
• ssh2-utf8-strings: SSH-2 message strings etc should be in UTF-8
• startup-unselected: If PuTTY starts without focus, the cursor does odd things.
• systray-breaks-ptr-hiding: System tray activity breaks pointer hiding
• telnet-url-userinfo: PuTTY should support the full telnet: URL syntax
• unclean-close-crash: Reports of crashes on unclean close (related to port forwarding?)
• win-message-loop: Using modal dialog boxes on Windows invokes a substandard message loop
• win-plink-stdin-handle-invalid: Plink: "Unable to read from standard input: The handle is invalid."
• win-tile: PuTTY interacts badly with Windows' automatic tiling
• win95-resolution: Problems with host name resolution on Win95; WinSock 2 implicated?
• window-title-charset: Window titles not interpreted according to current charset
• x11-ipv6-breakage: Reported X forwarding breakage due to IPv6
• xp-stickykeys-breaks-capslock: StickyKeys inverts sense of capslock on WinXP and Win2k3

Semi-bugs

These are things which might be bugs or might not, depending on your precise definition of what a bug is.

• false-positive-malware: PuTTY is persistently misreported as malware
• async-dns: DNS lookups are synchronous.
• black-pointer: Mouse pointer appears black on some systems
• da-response: PuTTY's response to DA is suboptimal
• dbcs-breakage: Double-byte character set (CJK, &c) display is broken
• fxp-short-reads: Support short reads in SFTP
• mapvirtualkeyex: Trouble with MapVirtualKeyEx in Korean Win98
• portfwd-multi: Port forwarding should cope better with already-used ports
• psftp-speedups: Further speedups for PSFTP
• pterm-settings: pterm's relationship to saved sessions should be clarified
• scroll-button-hang: Hangs on paste with middle button (Intellipoint implicated)
• serial-check-parity: Serial backends don't enable parity checking
• sgr21: PuTTY's interpretation of SGR 21 differs from Linux's
• ssh-rportfwd-addr-mismatch: Remote port forwarding fails due to address mismatch (Bitvise)
• unicode-select: Word-at-a-time selection configuration ignores Unicode
• win-fixed-ttf-underline: When using some bitmap TrueType fonts, underlined characters vanish
• win-redraw: Window redraw problems on Windows (white areas)
• win7-jumplist-duplicates: Windows "jump list" duplicates items between pinned and recent lists
• win98-focus: Win98 focuses taskbar after PuTTY window closed
• window-placement: Window placement circumvents Windows default rules
• winhelp-crash: Context help causes WinHelp crash after PuTTY help files upgraded

Wishlist

These are things that have been requested by users or which seem to me like a good idea. Not all of these are likely to be implemented without outside help, and some of them will positively never be implemented.

Plausible features we hope to get round to adding at some point:

• "fun": Just needs tuits, and not many of them.
  • auth-pref: Preference order for authentications
  • autoscroll-accel: Auto-scrolling while selecting should have variable speed
  • character-line-delay: Configurable per-character and per-line delays
  • cmdline-licence: Command-line tools should have an option to display licence
  • cmdline-x-display: Command-line option to set local X display
  • command-hooks: Hooks to run external commands (e.g. after forwarding set up)
  • emacs-keys: Emacs cursor-key etc mappings
  • handle-unimplemented: Handle SSH2_MSG_UNIMPLEMENTED more usefully
  • menu-bar: Menu bar in the PuTTY window
  • meta-bit: Option to have Alt key set the meta bit
  • multi-font: Multiple font selections
  • pageant-logging: Logging for Pageant
  • pageant-wildcard: Accept wildcards on Pageant command line
  • passthru-default-printer: Pass-through printing: option to go with Windows default printer
  • proxy-iprange: Support for IP address ranges (x.x.x.x/y) in proxy exclude list
  • pscp-check-first: PSCP could check source filespec before connecting
  • pscp-filemodes: Control of file permissions in PSCP and PSFTP
  • pscp-stdout: Make PSCP optionally log to stdout instead of stderr
  • psftp-progress: Progress indication for PSFTP
  • startup-fullscreen: Option to start up in full screen mode
  • terminfo: Maintain a terminfo for PuTTY's terminal emulator
  • window-title-keywords: Variable expansion in configured window title
• "tricky": Needs many tuits.
  • agentfwd-ssh.com: SSH-2 agent forwarding with ssh.com's product
  • avoid-msgbox: Avoid using message boxes for "connection closed" and friends
  • cmdline-any-option: Command-line general `-o Name=Value' type option
  • config-inheritance: Inheritance between saved sessions
  • config-locations: Store configuration in disk file, HKEY_ALL_USERS, other locations
  • dedicated-sharing-upstream: Separate dedicated utility to act as connection sharing upstream
  • do-text-splitting: Frontends need control over where do_paint() splits runs
  • http-digestauth: PuTTY should support HTTP Digest authentication for proxies
  • i18n: Framework for internationalisation
  • key-mapping: Generic key mapping facility
  • line-endings: Line ending conversion ("ASCII mode") in PSCP and PSFTP
  • log-mkdir: Create directories for log files automatically
  • many-sessions: Make life easier for people with lots of saved sessions
  • no-terminal-window: Ability to run without terminal window (for forwarding etc)
  • pageant-deferred-decrypt: Deferred key decryption in Pageant
  • pageant-key-confirm: Option to require confirmation of key use in Pageant
  • pageant-timeout: Key timeout in Pageant
  • port-mac: Port to Mac OS X
  • port-wince: Port to Windows CE (alias PocketPC)
  • portable-keyboard: Shared keyboard handler across platforms
  • proxy-logging: Log proxy connection setup etc
  • proxy-password-prompt: Should be able to prompt for a proxy password
  • pterm-scrollopt: Scroll-optimisation for pterm
  • reorder-sessions: Allow frequently used saved sessions to be easy to access
  • right-alt: Support for Right Alt on keyboards which don't call it AltGr
  • save-scrollback: Allow saving scrollback to a file (logging formatted terminal output)
  • search-scrollback: Searching facilities in the scrollback
  • srp-auth: SRP authentication (in SSH and perhaps also Telnet)
  • ssh-fingerprint-formats: Support more SSH public key fingerprint formats
  • ssh-url-scheme: Support for an "ssh" URL scheme
  • ssh2-openssh-certkeys: Support for OpenSSH certificates
  • status-bar: Status bar on the PuTTY window
  • system-menu: Expansions to the System menu
  • unicode-mappings: Compatibility mappings for Unicode characters unsupported by a font
  • win-enum-serial-ports: Enumerate serial ("COM") ports on Windows
  • windows-scrollopt: Scroll optimisations for Windows
  • winrt: Port PuTTY to Windows RT (aka Metro)
• "taxing": Needs external things we don't have (standards, users etc)
  • port-win32s: Port to Win32s

Features we're not sure about, or which probably won't get added unless someone else does the hard work:

• "fun": Just needs tuits, and not many of them.
  • ansisys-compat: Better compatibility with DOS's ANSI.SYS
  • bubble-babble: Bubble-babble encoding for host keys
  • cmdline-edit-session: Command-line option to edit a session rather than launching it
  • cmdline-environ: Command line stored in environment variable
  • emulate-3-buttons: Make left+right click emulate middle-click, like XFree86
  • env-passthrough: Option to pass through certain environment variables
  • fore-back: Specify foreground and background colours separately
  • function-keys-8bit: Option to start key sequences with 0x9B instead of 0x1B
  • hmac-sha2-512: Support for HMAC-SHA-512 in SSH-2
  • http-proxy-env: Honour the http_proxy et al environment variables
  • intel-keyboard: Keyboard mode to support Intel serial consoles
  • pageant-activity-ind: Visual/aural indication of Pageant activity
  • pageant-hibernate: Discard sensitive material in Pageant on hibernation
  • paste-on-release: PuTTY should paste when the paste button is released
  • portfwd-range: Allow port ranges in tunnel UI
  • psftp-paging: Paging on PSFTP directory listings
  • psftp-prompt: PSFTP should have a "prompt" command
  • reconnect-auto: Reconnect automatically if connection goes down
  • sel-colours: Make selection colours configurable
  • sgr-as-colours: Be able to change text colour or font in response to SGR Bold, Underline etc
  • term-reset-title: Perhaps terminal resets should reset window title(s)
  • triple-click-wrap: Perhaps triple-click select should take account of wrapped lines
  • two-way-keepalives: An alternative form of keepalive which is two-way
  • vt-utf8-keyboard: Keyboard mode to support Microsoft standard serial consoles
  • xterm-keyboard: Better xterm keyboard compatibility
• "tricky": Needs many tuits.
  • colour-scheme: Predefined colour schemes
  • cooked-printer: Feature-rich printer support with formatting control
  • cryptoapi: Use of MS Crypto API on Windows
  • dll-frontend: SSH client packaged as a DLL for use in other programs
  • drag-drop: Drag and drop support
  • gui-auth: Option to use GUI dialogs for authentication
  • gui-sftp: A GUI client for SFTP
  • horiz-scroll: Horizontal scrollbar
  • http-proxy-server: Present HTTP proxy interface to dynamic port forwarding
  • idn: Support for Internationalized Domain Names (IDNs)
  • ip-tos: Use of IP type-of-service field
  • key-formats-natively: Ability to use OpenSSH and ssh.com SSH-2 private keys directly (without first converting with PuTTYgen)
  • keyboard-copy: Should be able to copy to clipboard without mouse
  • log-timestamp: Timestamps in logs
  • mdpi: The mythical DLL Plugin Interface
  • multiple-connections: Managing multiple connections in one PuTTY (eg. tabbed windows, MDI)
  • pageant-unix-either-or: Agnostic agent/client mode in Unix Pageant
  • paste-fidelity: Extra fidelity in copy and paste operations
  • plink-background: Plink option to background after authentication
  • portfwd-ftp: Support for tunnelling FTP
  • print-screen: "Print screen" and similar functions
  • pscp-multi-remote-src: Perhaps PSCP should permit multiple remote sources
  • pscp-restart: Restart capability in PSCP
  • psftp-remget: Restart multiple-file operations in PSFTP
  • putty-screen-frontend: screen(1) front-end
  • puttygen-batch: Batch mode for Windows PuTTYgen
  • regexp-logging: Selective logging based on regular expressions
  • rsh-backend: rsh and rexec backends
  • scripting: Scripting support in PuTTY
  • scrollbar-left: Scroll bar on the left of the PuTTY window
  • selection-pause: Terminal output to pause while mouse selection in progress
  • session-icon: Custom, per-session configurable icons
  • sshfp-dns: Support for host key fingerprints in DNS
  • subsystem-publickey: Support for public key distribution subsystem `publickey'
  • toolbar: Toolbar on the PuTTY window
  • typographical-metrics: Make PuTTY use the typographical metrics in TrueType fonts
  • unicode-normalisation: Apply Unicode normalisation to combining characters
  • unix-persistent-bell: Persistent bell indication on Unix
  • url-launching: Launch URLs in the PuTTY window by clicking on them
  • zmodem: File transfers using Zmodem
• "taxing": Needs external things we don't have (standards, users etc)
  • cygwin-terminal-window: Use PuTTY as a local GUI terminal app for the Cygwin shell
  • function-keys: Function and other special keys don't do what people want
  • modified-fkeys: Unique codes for modified function/special keys
  • mosh: Compatibility with Mosh (mobile shell)
  • ntlm-auth: Ability to do NTLM authentication in various contexts (eg. proxy)
  • pageant-forwarding-path: Track and use the agent-forwarding path in Pageant
  • sco-ansi: Support for `SCO ANSI' terminal features
  • securid: SecurID authentication (`securid-1@ssh.com' etc)
  • smartcard-auth: PuTTY could use RSA keys held on smartcards
  • ssl: Support for SSL
  • vb-control: SSH client packaged as a Visual Basic component
• "mayhem": Probably impossible
  • moon-on-stick: The Moon, on a stick
  • win-command-prompt: Ability to backend on to a Windows command interpreter

Non-wish list

These are features we are actively opposed to seeing in PuTTY. Don't bother writing them and sending them to us! If you think you have a good argument why they would be good, feel free to plead for them, but generally I'll already have a good reason not to do them.

• accept-host-keys: An option to accept all SSH host keys
• banner-escape-codes: Interpret escape codes in pre-login banner
• compress-binaries: Compress shipped PuTTY binaries with a tool such as UPX
• control-window-pos: Remember window position, or allow it to be configured
• inhibit-close: Ability to remove close box from window
• locking-settings: Ability to lock settings against user changes
• mud-client: MUD-client-like features (separate input window, etc)
• osc: Escape sequence to execute command on the client side
• pageant-as-service: Ability to run Pageant as a Windows Service in NT/2000/etc
• plink-terminal: Terminal emulation in Plink
• port-knocking: Port knocking
• reconnect-remember-password: Remember entered password for reconnecting a dead session
• remember-password: Ability to store password in settings
• sftp-as-drive: Present SFTP as a mapped drive or file system
• system-tray: Use of the System tray
• terminal-emulations: Terminal emulations other than xterm/ECMA-48 (e.g. 3270)
• terminal-fanout: Send keyboard input to multiple active sessions
• transparency: Transparent or translucent PuTTY window
• tun-openssh: OpenSSH-compatible tun VPN support

Unclassified

Usually items we don't know enough about, or haven't yet thought about enough, to fully classify.

• cipher-selection: Cipher selection UI is messy and irrational
• foundry-ignore-bug: Foundry Networks 1.2.27 port has SSH_MSG_IGNORE bug
• fullscreen-menu-corner: Use other corners for menu in full-screen mode
• host-key-rollover: Host key/algorithm rollover not well supported
• host-key-sig-verify-fail: Occasional "server's host key did not match the signature supplied"
• netscreen-command: Trouble with netscreen firewalls and remote command
• psftp-batch-interact: PSFTP: continue interactively after a batch script
• ssh2-aesctr-openssh: Garbled packets from OpenSSH when using OpenSSL 0.9.8e
• ssh2-dropbear-ignore: An embedded version of Dropbear gets confused by SSH_MSG_IGNORE
• ssh2-romsshell-badstringlen: Embedded RomSShell server closes connection with "Bad string Length"
• sshcrcda-assertion-failed: Failed assertion in sshcrcda.c
• virtuallock: Use of VirtualLock() on Windows for sensitive material