Vulnerability Description
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in [email protected] and (if CBC is used) the [email protected] MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0, Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15, SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3, Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh crate before 0.40.2 for Rust.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Openbsd | Openssh | < 9.6 |
| Putty | Putty | < 0.80 |
| Filezilla-Project | Filezilla Client | < 3.66.4 |
| Apple | Macos | - |
| Panic | Transmit 5 | < 5.10.4 |
| Panic | Nova | < 11.8 |
| Roumenpetrov | Pkixssh | < 14.4 |
| Winscp | Winscp | < 6.2.2 |
| Bitvise | Ssh Client | < 9.33 |
| Bitvise | Ssh Server | < 9.32 |
| Lancom-Systems | Lcos | <= 3.66.4 |
| Lancom-Systems | Lcos Fx | - |
| Lancom-Systems | Lcos Lx | - |
| Lancom-Systems | Lcos Sx | 4.20 |
| Lancom-Systems | Lanconfig | - |
| Vandyke | Securecrt | < 9.4.3 |
| Libssh | Libssh | < 0.10.6 |
| Net-Ssh | Net-Ssh | 7.2.0 |
| Ssh2 Project | Ssh2 | <= 1.11.0 |
| Proftpd | Proftpd | <= 1.3.8b |
Related Weaknesses (CWE)
References
- http://packetstormsecurity.com/files/176280/Terrapin-SSH-Connection-Weakening.htThird Party AdvisoryVDB Entry
- http://seclists.org/fulldisclosure/2024/Mar/21Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2023/12/18/3Mailing List
- http://www.openwall.com/lists/oss-security/2023/12/19/5Mailing List
- http://www.openwall.com/lists/oss-security/2023/12/20/3Mailing ListMitigation
- http://www.openwall.com/lists/oss-security/2024/03/06/3Mailing List
- http://www.openwall.com/lists/oss-security/2024/04/17/8Mailing List
- https://access.redhat.com/security/cve/cve-2023-48795Third Party Advisory
- https://arstechnica.com/security/2023/12/hackers-can-break-ssh-channel-integrityPress/Media Coverage
- https://bugs.gentoo.org/920280Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=2254210Issue Tracking
- https://bugzilla.suse.com/show_bug.cgi?id=1217950Issue Tracking
- https://crates.io/crates/thrussh/versionsRelease Notes
- https://filezilla-project.org/versions.phpRelease Notes
- https://forum.netgate.com/topic/184941/terrapin-ssh-attackIssue Tracking
FAQ
What is CVE-2023-48795?
CVE-2023-48795 is a vulnerability with a CVSS score of 5.9 (MEDIUM). The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from ...
How severe is CVE-2023-48795?
CVE-2023-48795 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2023-48795?
Check the references section above for vendor advisories and patch information. Affected products include: Openbsd Openssh, Putty Putty, Filezilla-Project Filezilla Client, Apple Macos, Panic Transmit 5.