===================================================================== CERT-Renater Note d'Information No. 2022/VULN353 _____________________________________________________________________ DATE : 04/10/2022 HARDWARE PLATFORM(S): / OPERATING SYSTEM(S): Systems running OpenSSH versions prior to 9.1. ===================================================================== https://lists.mindrot.org/pipermail/openssh-unix-announce/2022-October/000149.html _____________________________________________________________________ OpenSSH 9.1 has just been released. It will be available from the mirrors listed at https://www.openssh.com/ shortly. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: https://www.openssh.com/donations.html Changes since OpenSSH 9.0 ========================= This release is focused on bug fixing. Security ======== This release contains fixes for three minor memory safety problems. None are believed to be exploitable, but we report most memory safety problems as potential security vulnerabilities out of caution. * ssh-keyscan(1): fix a one-byte overflow in SSH- banner processing. Reported by Qualys * ssh-keygen(1): double free() in error path of file hashing step in signing/verify code; GHPR333 * ssh-keysign(8): double-free in error path introduced in openssh-8.9 Potentially-incompatible changes -------------------------------- * The portable OpenSSH project now signs commits and release tags using git's recent SSH signature support. The list of developer signing keys is included in the repository as .git_allowed_signers and is cross-signed using the PGP key that is still used to sign release artifacts: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc * ssh(1), sshd(8): SetEnv directives in ssh_config and sshd_config are now first-match-wins to match other directives. Previously if an environment variable was multiply specified the last set value would have been used. bz3438 * ssh-keygen(8): ssh-keygen -A (generate all default host key types) will no longer generate DSA keys, as these are insecure and have not been used by default for some years. New features ------------ * ssh(1), sshd(8): add a RequiredRSASize directive to set a minimum RSA key length. Keys below this length will be ignored for user authentication and for host authentication in sshd(8). ssh(1) will terminate a connection if the server offers an RSA key that falls below this limit, as the SSH protocol does not include the ability to retry a failed key exchange. * sftp-server(8): add a "users-groups-by-id@...nssh.com" extension request that allows the client to obtain user/group names that correspond to a set of uids/gids. * sftp(1): use "users-groups-by-id@...nssh.com" sftp-server extension (when available) to fill in user/group names for directory listings. * sftp-server(8): support the "home-directory" extension request defined in draft-ietf-secsh-filexfer-extensions-00. This overlaps a bit with the existing "expand-path@...nssh.com", but some other clients support it. * ssh-keygen(1), sshd(8): allow certificate validity intervals, sshsig verification times and authorized_keys expiry-time options to accept dates in the UTC time zone in addition to the default of interpreting them in the system time zone. YYYYMMDD and YYMMDDHHMM[SS] dates/times will be interpreted as UTC if suffixed with a 'Z' character. Also allow certificate validity intervals to be specified in raw seconds-since-epoch as hex value, e.g. -V 0x1234:0x4567890. This is intended for use by regress tests and other tools that call ssh-keygen as part of a CA workflow. bz3468 * sftp(1): allow arguments to the sftp -D option, e.g. sftp -D "/usr/libexec/sftp-server -el debug3" * ssh-keygen(1): allow the existing -U (use agent) flag to work with "-Y sign" operations, where it will be interpreted to require that the private keys is hosted in an agent; bz3429 Bugfixes -------- * ssh-keygen(1): implement the "verify-required" certificate option. This was already documented when support for user-verified FIDO keys was added, but the ssh-keygen(1) code was missing. * ssh-agent(1): hook up the restrict_websafe command-line flag; previously the flag was accepted but never actually used. * sftp(1): improve filename tab completions: never try to complete names to non-existent commands, and better match the completion type (local or remote filename) against the argument position being completed. * ssh-keygen(1), ssh(1), ssh-agent(1): several fixes to FIDO key handling, especially relating to keys that request user-verification. These should reduce the number of unnecessary PIN prompts for keys that support intrinsic user verification. GHPR302, GHPR329 * ssh-keygen(1): when enrolling a FIDO resident key, check if a credential with matching application and user ID strings already exists and, if so, prompt the user for confirmation before overwriting the credential. GHPR329 * sshd(8): improve logging of errors when opening authorized_keys files. bz2042 * ssh(1): avoid multiplexing operations that could cause SIGPIPE from causing the client to exit early. bz3454 * ssh_config(5), sshd_config(5): clarify that the RekeyLimit directive applies to both transmitted and received data. GHPR328 * ssh-keygen(1): avoid double fclose() in error path. * sshd(8): log an error if pipe() fails while accepting a connection. bz3447 * ssh(1), ssh-keygen(1): fix possible NULL deref when built without FIDO support. bz3443 * ssh-keyscan(1): add missing *-sk types to ssh-keyscan manpage. GHPR294. * sshd(8): ensure that authentication passwords are cleared from memory in error paths. GHPR286 * ssh(1), ssh-agent(1): avoid possibility of notifier code executing kill(-1). GHPR286 * ssh_config(5): note that the ProxyJump directive also accepts the same tokens as ProxyCommand. GHPR305. * scp(1): do not not ftruncate(3) files early when in sftp mode. The previous behaviour of unconditionally truncating the destination file would cause "scp ~/foo localhost:foo" and the reverse "scp localhost:foo ~/foo" to delete all the contents of their destination. bz3431 * ssh-keygen(1): improve error message when 'ssh-keygen -Y sign' is unable to load a private key; bz3429 * sftp(1), scp(1): when performing operations that glob(3) a remote path, ensure that the implicit working directory used to construct that path escapes glob(3) characters. This prevents glob characters from being processed in places they shouldn't, e.g. "cd /tmp/a*/", "get *.txt" should have the get operation treat the path "/tmp/a*" literally and not attempt to expand it. * ssh(1), sshd(8): be stricter in which characters will be accepted in specifying a mask length; allow only 0-9. GHPR278 * ssh-keygen(1): avoid printing hash algorithm twice when dumping a KRL * ssh(1), sshd(8): continue running local I/O for open channels during SSH transport rekeying. This should make ~-escapes work in the client (e.g. to exit) if the connection happened to have stalled during a rekey event. * ssh(1), sshd(8): avoid potential poll() spin during rekeying * Further hardening for sshbuf internals: disallow "reparenting" a hierarchical sshbuf and zero the entire buffer if reallocation fails. GHPR287 Portability ----------- * ssh(1), ssh-keygen(1), sshd(8): automatically enable the built-in FIDO security key support if libfido2 is found and usable, unless --without-security-key-builtin was requested. * ssh(1), ssh-keygen(1), sshd(8): many fixes to make the WinHello FIDO device usable on Cygwin. The windows://hello FIDO device will be automatically used by default on this platform unless requested otherwise, or when probing resident FIDO credentials (an operation not currently supported by WinHello). * Portable OpenSSH: remove workarounds for obsolete and unsupported versions of OpenSSL libcrypto. In particular, this release removes fallback support for OpenSSL that lacks AES-CTR or AES-GCM. Those AES cipher modes were added to OpenSSL prior to the minimum version currently supported by OpenSSH, so this is not expected to impact any currently supported configurations. * sshd(8): fix SANDBOX_SECCOMP_FILTER_DEBUG on current Linux/glibc * All: resync and clean up internal CSPRNG code. * scp(1), sftp(1), sftp-server(8): avoid linking these programs with unnecessary libraries. They are no longer linked against libz and libcrypto. This may be of benefit to space constrained systems using any of those components in isolation. * sshd(8): add AUDIT_ARCH_PPC to supported seccomp sandbox architectures. * configure: remove special casing of crypt(). configure will no longer search for crypt() in libcrypto, as it was removed from there years ago. configure will now only search libc and libcrypt. * configure: refuse to use OpenSSL 3.0.4 due to potential RCE in its RSA implementation (CVE-2022-2274) on x86_64. * All: request 1.1x API compatibility for OpenSSL >=3.x; GHPR#322 * ssh(1), ssh-keygen(1), sshd(8): fix a number of missing includes required by the XMSS code on some platforms. * sshd(8): cache timezone data in capsicum sandbox. Checksums: ========== - SHA1 (openssh-9.1.tar.gz) = 3ae2d6a3a695d92778c4c4567dcd6ad481092f6c - SHA256 (openssh-9.1.tar.gz) = QKfVArlcItV+e8V1Th85TL5//5d/AvOUhYOeHMDEGuE= - SHA1 (openssh-9.1p1.tar.gz) = 15545440268967511d3194ebf20bcd0c7ff3fcc9 - SHA256 (openssh-9.1p1.tar.gz) = GfhQCcfj4jeH8CNvuxV4OSq01L+fjsX+a8HNfov90og= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available from the mirror sites: https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/RELEASE_KEY.asc Reporting Bugs: =============== - Please read https://www.openssh.com/report.html Security bugs should be reported directly to openssh@...nssh.com ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 23/25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email:cert@support.renater.fr + =========================================================