OpenSSH 7.5 was released on 2017-03-20. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. OpenSSH also includes transitional support for the legacy SSH 1.3 and 1.5 protocols that may be enabled at compile-time. 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: http://www.openssh.com/donations.html Future deprecation notice ========================= We plan on retiring more legacy cryptography in future releases, specifically: * In the next major release (expected June-August), removing remaining support for the SSH v.1 protocol (currently client-only and compile- time disabled). * In the same release, removing support for Blowfish and RC4 ciphers and the RIPE-MD160 HMAC. (These are currently run-time disabled). * In the same release, removing the remaining CBC ciphers from being offered by default in the client (These have not been offered in sshd by default for several years). * Refusing all RSA keys smaller than 1024 bits (the current minimum is 768 bits) This list reflects our current intentions, but please check the final release notes for future releases. Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * This release deprecates the sshd_config UsePrivilegeSeparation option, thereby making privilege separation mandatory. Privilege separation has been on by default for almost 15 years and sandboxing has been on by default for almost the last five. * The format of several log messages emitted by the packet code has changed to include additional information about the user and their authentication state. Software that monitors ssh/sshd logs may need to account for these changes. For example: Connection closed by user x 1.1.1.1 port 1234 [preauth] Connection closed by authenticating user x 10.1.1.1 port 1234 [preauth] Connection closed by invalid user x 1.1.1.1 port 1234 [preauth] Affected messages include connection closure, timeout, remote disconnection, negotiation failure and some other fatal messages generated by the packet code. * [Portable OpenSSH only] This version removes support for building against OpenSSL versions prior to 1.0.1. OpenSSL stopped supporting versions prior to 1.0.1 over 12 months ago (i.e. they no longer receive fixes for security bugs). Changes since OpenSSH 7.4 ========================= This is a bugfix release. Security -------- * ssh(1), sshd(8): Fix weakness in CBC padding oracle countermeasures that allowed a variant of the attack fixed in OpenSSH 7.3 to proceed. Note that the OpenSSH client disables CBC ciphers by default, sshd offers them as lowest-preference options and will remove them by default entriely in the next release. Reported by Jean Paul Degabriele, Kenny Paterson, Martin Albrecht and Torben Hansen of Royal Holloway, University of London. * sftp-client(1): [portable OpenSSH only] On Cygwin, a client making a recursive file transfer could be maniuplated by a hostile server to perform a path-traversal attack. creating or modifying files outside of the intended target directory. Reported by Jann Horn of Google Project Zero. New Features ------------ * ssh(1), sshd(8): Support "=-" syntax to easily remove methods from algorithm lists, e.g. Ciphers=-*cbc. bz#2671 Bugfixes -------- * sshd(1): Fix NULL dereference crash when key exchange start messages are sent out of sequence. * ssh(1), sshd(8): Allow form-feed characters to appear in configuration files. * sshd(8): Fix regression in OpenSSH 7.4 support for the server-sig-algs extension, where SHA2 RSA signature methods were not being correctly advertised. bz#2680 * ssh(1), ssh-keygen(1): Fix a number of case-sensitivity bugs in known_hosts processing. bz#2591 bz#2685 * ssh(1): Allow ssh to use certificates accompanied by a private key file but no corresponding plain *.pub public key. bz#2617 * ssh(1): When updating hostkeys using the UpdateHostKeys option, accept RSA keys if HostkeyAlgorithms contains any RSA keytype. Previously, ssh could ignore RSA keys when only the ssh-rsa-sha2-* methods were enabled in HostkeyAlgorithms and not the old ssh-rsa method. bz#2650 * ssh(1): Detect and report excessively long configuration file lines. bz#2651 * Merge a number of fixes found by Coverity and reported via Redhat and FreeBSD. Includes fixes for some memory and file descriptor leaks in error paths. bz#2687 * ssh-keyscan(1): Correctly hash hosts with a port number. bz#2692 * ssh(1), sshd(8): When logging long messages to stderr, don't truncate "\r\n" if the length of the message exceeds the buffer. bz#2688 * ssh(1): Fully quote [host]:port in generated ProxyJump/-J command- line; avoid confusion over IPv6 addresses and shells that treat square bracket characters specially. * ssh-keygen(1): Fix corruption of known_hosts when running "ssh-keygen -H" on a known_hosts containing already-hashed entries. * Fix various fallout and sharp edges caused by removing SSH protocol 1 support from the server, including the server banner string being incorrectly terminated with only \n (instead of \r\n), confusing error messages from ssh-keyscan bz#2583 and a segfault in sshd if protocol v.1 was enabled for the client and sshd_config contained references to legacy keys bz#2686. * ssh(1), sshd(8): Free fd_set on connection timeout. bz#2683 * sshd(8): Fix Unix domain socket forwarding for root (regression in OpenSSH 7.4). * sftp(1): Fix division by zero crash in "df" output when server returns zero total filesystem blocks/inodes. * ssh(1), ssh-add(1), ssh-keygen(1), sshd(8): Translate OpenSSL errors encountered during key loading to more meaningful error codes. bz#2522 bz#2523 * ssh-keygen(1): Sanitise escape sequences in key comments sent to printf but preserve valid UTF-8 when the locale supports it; bz#2520 * ssh(1), sshd(8): Return reason for port forwarding failures where feasible rather than always "administratively prohibited". bz#2674 * sshd(8): Fix deadlock when AuthorizedKeysCommand or AuthorizedPrincipalsCommand produces a lot of output and a key is matched early. bz#2655 * Regression tests: several reliability fixes. bz#2654 bz#2658 bz#2659 * ssh(1): Fix typo in ~C error message for bad port forward cancellation. bz#2672 * ssh(1): Show a useful error message when included config files can't be opened; bz#2653 * sshd(8): Make sshd set GSSAPIStrictAcceptorCheck=yes as the manual page (previously incorrectly) advertised. bz#2637 * sshd_config(5): Repair accidentally-deleted mention of %k token in AuthorizedKeysCommand; bz#2656 * sshd(8): Remove vestiges of previously removed LOGIN_PROGRAM; bz#2665 * ssh-agent(1): Relax PKCS#11 whitelist to include libexec and common 32-bit compatibility library directories. * sftp-client(1): Fix non-exploitable integer overflow in SSH2_FXP_NAME response handling. * ssh-agent(1): Fix regression in 7.4 of deleting PKCS#11-hosted keys. It was not possible to delete them except by specifying their full physical path. bz#2682 Portability ----------- * sshd(8): Avoid sandbox errors for Linux S390 systems using an ICA crypto coprocessor. * sshd(8): Fix non-exploitable weakness in seccomp-bpf sandbox arg inspection. * ssh(1): Fix X11 forwarding on OSX where X11 was being started by launchd. bz#2341 * ssh-keygen(1), ssh(1), sftp(1): Fix output truncation for various that contain non-printable characters where the codeset in use is ASCII. * build: Fix builds that attempt to link a kerberised libldns. bz#2603 * build: Fix compilation problems caused by unconditionally defining _XOPEN_SOURCE in wide character detection. * sshd(8): Fix sandbox violations for clock_gettime VSDO syscall fallback on some Linux/X32 kernels. bz#2142 Checksums: ========== - SHA1 (openssh-7.5.tar.gz) = 81384df377e38551f7659a4c250383d0bbd25341 - SHA1 (openssh-7.5p1.tar.gz) = 5e8f185d00afb4f4f89801e9b0f8b9cee9d87ebd - SHA256 (openssh-7.5.tar.gz) = Gmk8jOdGdKa7NixUN5J+bTMfeum5Vx8Nv+leAdQNq3U= - SHA256 (openssh-7.5p1.tar.gz) = mEbjxfq58FR0ALTSwBeZL5FCIrP9H47ubH3GvF5Z+fA= 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 as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com OpenSSH is brought to you by Markus Friedl, Niels Provos, Theo de Raadt, Kevin Steves, Damien Miller, Darren Tucker, Jason McIntyre, Tim Rice and Ben Lindstrom.