Recent Releases

2025.8903 Feb 2026 03:15 minor bugfix: Security: Avoid privilege escalation via unix stream forwarding in Dropbear server. Other programs on a system may authenticate unix sockets via SO_PEERCRED, which would be root user for Dropbear forwarded connections, allowing root privilege escalation. Reported by Turistu, and thanks for advice on the. This is tracked as CVE-2025-14282, and affects 2024.84 to 2025.88. It is by dropping privileges of the dropbear process after authentication. Unix stream sockets are now disallowed when a forced command is used, either with authorized_key restrictions or. "dropbear -c command". In previous affected releases running with "dropbear -j" (will also disable TCP forwarding) or building with localoptions.h/distrooptions.h. "#define DROPBEAR_SVR_LOCALSTREAMFWD 0" is a mitigation. Security: Include scp for CVE-2019-6111. This allowed a malicious server to overwrite arbitrary local files. The missing was reported by Ashish Kunwar. Server dropping privileges post-auth is enabled by default. This requires setresgid() support, so some platforms such as netbsd or macos will have to disable DROPBEAR_SVR_DROP_PRIVS in localoptions.h. Unix stream forwarding is not available if DROPBEAR_SVR_DROP_PRIVS is disabled. Remote server TCP socket forwarding will now use OS privileged port restrictions rather than having a "allow =1024 for non-root" rule. A future release may implement privilege dropping for netbsd/macos. a regression in 2025.87 when RSA and DSS are not built. This would lead to a crash at startup with bad_bufptr(). Reported by Dani Schmitt and Sebastian Priebe. Don't limit channel window to 500MB. That is could cause stuck connections if peers advise a large window and don't send an increment within 500MB. Affects SSH.NET https://github.com/sshnet/SSH.NET//1671 Reported by Rob Hague. Ignore -g -s when passwords arent enabled. Patch from Norbert Lange. Ignore -m (disable MOTD), -j/-k (tcp forwarding) when not enabled. Report SIGBUS and SIGTRAP signals.
2025.8815 Jun 2025 03:15 minor security: Security: Don't allow dbclient hostname arguments to be interpreted by the shell. Dbclient hostname arguments with a comma (for multihop) would be. Passed to the shell which could result in running arbitrary shell Commands locally. That could be a security in situations Where dbclient is passed untrusted hostname arguments. Now the multihop command is executed directly, no shell is involved. Thanks to Marcin Nowak for the report, tracked as CVE-2025-47203. Compatibility for htole64 and htole32, regression in 2025.87 Patch from Peter Fichtner to work with old GCC versions, and. Patch from Matt Robinson to check different header files. Building on older compilers or libc that don't support. Static_assert(). Regression in 2025.87 Support R in the client to force a key re-exchange. Improve strict KEX handling. Dropbear previously would allow other. Packets at the end of key exchange prior to receiving the remote Peer's NEWKEYS message, which should be forbidden by strict KEX. Reported by Fabian BΓ€umer.
2025.8726 Mar 2025 02:25 minor feature: Note for compatibility/configuration changes Disable SHA-1 algorithms by default. SHA-1 has known weakness and. Most implementations support alternatives. Add post-quantum key exchange. These avoid the possibility of current. Stored traffic being decrypted using a possible future quantum Computer. Sntrup761 added by Matt Johnston, using sntrup761 implementation from Daniel J. Bernstein, Chitchanok Chuengsatiansup, Tanja Lange and Christine van Vredendaal, with integration work from OpenSSH. ML-KEM added by Loganaden Velvindron, Jaykishan Mutkawoa, Kavish Nadan. Using libcrux, also based on OpenSSH work. These do increase code size, at least sntrup761 is recommended. See default_options.h Decompression is disabled on the server, compression is still supported. This avoids attack surface for zlib and saves runtime memory. Add -D server flag to specify authorized_keys directory, from Darren Tucker. Include remote host in "Login attempt with wrong user" message for fail2ban. Patch from MichaIng. Workaround writing hostkeys on FUSE filesystem that don't. Support hardlinks, reported by elijahr. Truncated error messages such as host key mismatch. Preference aes256 ahead of aes128 for the client. chacha20-poly1305 is still first preference. Ubsan failure in curve25519 code, reported by Steven Bytnar. Has no effect on execution.
2024.8604 Jan 2025 21:31 minor bugfix: failure on concurrent channel open/. This was a regression in 2022.82, reported by rsflo in Github #321. failed assertion in common-channel.c:705: !channel- sent_. Print remote host after "Login attempt for nonexistent user" log entry to assist fail2ban. from MichaIng, the format changed in 2020.79. Dropbear now exits with exit status 0 on SIGINT/SIGTERM. This is a more graceful behaviour for "systemctl stop dropbear". Reported by Ninad Palsule. New IDENT_VERSION_PART config allows customising some of the SSH version string. From Marius Dinu. building SK_KEYS with just one of ECDSA or ED25519 From Marius Dinu. dbclient "-m help" and "-c help" without a hostname. Patch from Darren Tucker. Remove fprintf/gettimeofday from sigchld handler when running with verbose trace enabled. Improved configure help output, from Mikel Olasagasti Uranga. Compile for GNU Hurd, from Guilhem Moulin. Support running test_aslr without venv, from Guilhem Moulin. Compilation for older compilers, and better build tests. Update some test infrastructure versions of python packages, github actions, and github runner OSes.