CVE-2023-48795

5.9 MEDIUM
Published: December 18, 2023 Modified: November 04, 2025

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 chacha20-poly1305@openssh.com and (if CBC is used) the -etm@openssh.com 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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
http://seclists.org/fulldisclosure/2024/Mar/21
Source: cve@mitre.org
Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/12/20/3
Source: cve@mitre.org
Mailing List Mitigation
https://access.redhat.com/security/cve/cve-2023-48795
Source: cve@mitre.org
Third Party Advisory
https://bugs.gentoo.org/920280
Source: cve@mitre.org
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2254210
Source: cve@mitre.org
Issue Tracking
https://bugzilla.suse.com/show_bug.cgi?id=1217950
Source: cve@mitre.org
Issue Tracking
https://crates.io/crates/thrussh/versions
Source: cve@mitre.org
Release Notes
https://filezilla-project.org/versions.php
Source: cve@mitre.org
Release Notes
https://github.com/NixOS/nixpkgs/pull/275249
Source: cve@mitre.org
Release Notes
https://github.com/advisories/GHSA-45x7-px36-x8w8
Source: cve@mitre.org
Third Party Advisory
https://github.com/apache/mina-sshd/issues/445
Source: cve@mitre.org
Issue Tracking
https://github.com/connectbot/sshlib/compare/2.2.21...2.2.22
Source: cve@mitre.org
Third Party Advisory
https://github.com/cyd01/KiTTY/issues/520
Source: cve@mitre.org
Issue Tracking
https://github.com/hierynomus/sshj/issues/916
Source: cve@mitre.org
Issue Tracking
https://github.com/janmojzis/tinyssh/issues/81
Source: cve@mitre.org
Issue Tracking
https://github.com/libssh2/libssh2/pull/1291
Source: cve@mitre.org
Mitigation
https://github.com/mwiede/jsch/issues/457
Source: cve@mitre.org
Issue Tracking
https://github.com/mwiede/jsch/pull/461
Source: cve@mitre.org
Release Notes
https://github.com/paramiko/paramiko/issues/2337
Source: cve@mitre.org
Issue Tracking
https://github.com/proftpd/proftpd/issues/456
Source: cve@mitre.org
Issue Tracking
https://github.com/rapier1/hpn-ssh/releases
Source: cve@mitre.org
Release Notes
https://github.com/ronf/asyncssh/tags
Source: cve@mitre.org
Release Notes
https://github.com/ssh-mitm/ssh-mitm/issues/165
Source: cve@mitre.org
Issue Tracking
https://gitlab.com/libssh/libssh-mirror/-/tags
Source: cve@mitre.org
Release Notes
https://help.panic.com/releasenotes/transmit5/
Source: cve@mitre.org
Release Notes
https://lists.debian.org/debian-lts-announce/2024/01/msg00013.html
Source: cve@mitre.org
Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/01/msg00014.html
Source: cve@mitre.org
Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/04/msg00016.html
Source: cve@mitre.org
Mailing List Third Party Advisory
https://matt.ucc.asn.au/dropbear/CHANGES
Source: cve@mitre.org
Release Notes
https://news.ycombinator.com/item?id=38684904
Source: cve@mitre.org
Issue Tracking
https://news.ycombinator.com/item?id=38685286
Source: cve@mitre.org
Issue Tracking
https://news.ycombinator.com/item?id=38732005
Source: cve@mitre.org
Issue Tracking
https://nova.app/releases/#v11.8
Source: cve@mitre.org
Release Notes
https://oryx-embedded.com/download/#changelog
Source: cve@mitre.org
Release Notes
https://roumenpetrov.info/secsh/#news20231220
Source: cve@mitre.org
Release Notes
https://security.gentoo.org/glsa/202312-16
Source: cve@mitre.org
Third Party Advisory
https://security.gentoo.org/glsa/202312-17
Source: cve@mitre.org
Third Party Advisory
https://security.netapp.com/advisory/ntap-20240105-0004/
Source: cve@mitre.org
Third Party Advisory
https://support.apple.com/kb/HT214084
Source: cve@mitre.org
Third Party Advisory
https://thorntech.com/cve-2023-48795-and-sftp-gateway/
Source: cve@mitre.org
Third Party Advisory
https://twitter.com/TrueSkrillor/status/1736774389725565005
Source: cve@mitre.org
Press/Media Coverage
https://ubuntu.com/security/CVE-2023-48795
Source: cve@mitre.org
Vendor Advisory
https://winscp.net/eng/docs/history#6.2.2
Source: cve@mitre.org
Release Notes
https://www.bitvise.com/ssh-server-version-history
Source: cve@mitre.org
Release Notes
https://www.debian.org/security/2023/dsa-5586
Source: cve@mitre.org
Issue Tracking
https://www.debian.org/security/2023/dsa-5588
Source: cve@mitre.org
Issue Tracking
https://www.netsarang.com/en/xshell-update-history/
Source: cve@mitre.org
Release Notes
https://www.openssh.com/openbsd.html
Source: cve@mitre.org
Release Notes
https://www.openssh.com/txt/release-9.6
Source: cve@mitre.org
Release Notes
https://www.openwall.com/lists/oss-security/2023/12/20/3
Source: cve@mitre.org
Mailing List Mitigation
https://www.paramiko.org/changelog.html
Source: cve@mitre.org
Release Notes
https://www.terrapin-attack.com
Source: cve@mitre.org
Exploit
https://www.theregister.com/2023/12/20/terrapin_attack_ssh
Source: cve@mitre.org
Press/Media Coverage
http://packetstormsecurity.com/files/176280/Terrapin-SSH-Connection-Weakening.html
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory VDB Entry
http://seclists.org/fulldisclosure/2024/Mar/21
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/12/18/3
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List
http://www.openwall.com/lists/oss-security/2023/12/19/5
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List
http://www.openwall.com/lists/oss-security/2023/12/20/3
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Mitigation
http://www.openwall.com/lists/oss-security/2024/03/06/3
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List
http://www.openwall.com/lists/oss-security/2024/04/17/8
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List
https://access.redhat.com/security/cve/cve-2023-48795
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://bugs.gentoo.org/920280
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2254210
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://bugzilla.suse.com/show_bug.cgi?id=1217950
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://crates.io/crates/thrussh/versions
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://filezilla-project.org/versions.php
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://forum.netgate.com/topic/184941/terrapin-ssh-attack
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/NixOS/nixpkgs/pull/275249
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/PowerShell/Win32-OpenSSH/issues/2189
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/PowerShell/Win32-OpenSSH/releases/tag/v9.5.0.0p1-Beta
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/TeraTermProject/teraterm/releases/tag/v5.1
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/advisories/GHSA-45x7-px36-x8w8
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://github.com/apache/mina-sshd/issues/445
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/connectbot/sshlib/compare/2.2.21...2.2.22
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://github.com/cyd01/KiTTY/issues/520
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/drakkan/sftpgo/releases/tag/v2.5.6
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/erlang/otp/releases/tag/OTP-26.2.1
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/hierynomus/sshj/issues/916
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/janmojzis/tinyssh/issues/81
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/libssh2/libssh2/pull/1291
Source: af854a3a-2127-422b-91ae-364da2661108
Mitigation
https://github.com/mwiede/jsch/compare/jsch-0.2.14...jsch-0.2.15
Source: af854a3a-2127-422b-91ae-364da2661108
Product
https://github.com/mwiede/jsch/issues/457
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/mwiede/jsch/pull/461
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/openssh/openssh-portable/commits/master
Source: af854a3a-2127-422b-91ae-364da2661108
Patch
https://github.com/paramiko/paramiko/issues/2337
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTES
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/proftpd/proftpd/issues/456
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/rapier1/hpn-ssh/releases
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/ronf/asyncssh/blob/develop/docs/changes.rst
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/ronf/asyncssh/tags
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://github.com/ssh-mitm/ssh-mitm/issues/165
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://github.com/warp-tech/russh/releases/tag/v0.40.2
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://gitlab.com/libssh/libssh-mirror/-/tags
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://groups.google.com/g/golang-announce/c/-n5WqVC18LQ
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List
https://groups.google.com/g/golang-announce/c/qA3XtxvMUyg
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List
https://help.panic.com/releasenotes/transmit5/
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://lists.debian.org/debian-lts-announce/2023/12/msg00017.html
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List
https://lists.debian.org/debian-lts-announce/2024/01/msg00013.html
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/01/msg00014.html
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/04/msg00016.html
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory
https://matt.ucc.asn.au/dropbear/CHANGES
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://news.ycombinator.com/item?id=38684904
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://news.ycombinator.com/item?id=38685286
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://news.ycombinator.com/item?id=38732005
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://nova.app/releases/#v11.8
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://oryx-embedded.com/download/#changelog
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2024-0002
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://roumenpetrov.info/secsh/#news20231220
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://security-tracker.debian.org/tracker/CVE-2023-48795
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
https://security-tracker.debian.org/tracker/source-package/libssh2
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
https://security-tracker.debian.org/tracker/source-package/proftpd-dfsg
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
https://security-tracker.debian.org/tracker/source-package/trilead-ssh2
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://security.gentoo.org/glsa/202312-16
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://security.gentoo.org/glsa/202312-17
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://security.netapp.com/advisory/ntap-20240105-0004/
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://support.apple.com/kb/HT214084
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://thorntech.com/cve-2023-48795-and-sftp-gateway/
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://twitter.com/TrueSkrillor/status/1736774389725565005
Source: af854a3a-2127-422b-91ae-364da2661108
Press/Media Coverage
https://ubuntu.com/security/CVE-2023-48795
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
https://winscp.net/eng/docs/history#6.2.2
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.bitvise.com/ssh-client-version-history#933
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.bitvise.com/ssh-server-version-history
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.crushftp.com/crush10wiki/Wiki.jsp?page=Update
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.debian.org/security/2023/dsa-5586
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://www.debian.org/security/2023/dsa-5588
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking
https://www.freebsd.org/security/advisories/FreeBSD-SA-23:19.openssh.asc
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.lancom-systems.de/service-support/allgemeine-sicherheitshinweise#c243508
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
https://www.netsarang.com/en/xshell-update-history/
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.openssh.com/openbsd.html
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.openssh.com/txt/release-9.6
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.openwall.com/lists/oss-security/2023/12/18/2
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List
https://www.openwall.com/lists/oss-security/2023/12/20/3
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Mitigation
https://www.paramiko.org/changelog.html
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.suse.com/c/suse-addresses-the-ssh-v2-protocol-terrapin-attack-aka-cve-2023-48795/
Source: af854a3a-2127-422b-91ae-364da2661108
Press/Media Coverage
https://www.terrapin-attack.com
Source: af854a3a-2127-422b-91ae-364da2661108
Exploit
https://www.theregister.com/2023/12/20/terrapin_attack_ssh
Source: af854a3a-2127-422b-91ae-364da2661108
Press/Media Coverage
https://www.vandyke.com/products/securecrt/history.txt
Source: af854a3a-2127-422b-91ae-364da2661108
Release Notes
https://www.vicarius.io/vsociety/posts/cve-2023-48795-detect-openssh-vulnerabilit
Source: af854a3a-2127-422b-91ae-364da2661108
Exploit Third Party Advisory
https://www.vicarius.io/vsociety/posts/cve-2023-48795-mitigate-openssh-vulnerability
Source: af854a3a-2127-422b-91ae-364da2661108
Exploit Third Party Advisory

252 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.9 / 10.0
EPSS (Exploit Probability)
57.8%
98th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

redhat dropbear_ssh_project gentoo trilead filezilla-project libssh2 freebsd oryx-embedded matez ssh +32 more