CVE-2023-48795

5.9 medium exploit ×5 SSVC exploitation: poc Modified

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.

Fix

Public exploits 5

Mr-Whiskerss/SSH-Terrapin-Prefix-Truncation-Weakness-CVE-2023-48795-Checker PoC on GitHub
TrixSec/CVE-2023-48795 PoC on GitHub
breaksek/CVE-2023-48795 PoC on GitHub
hav0cx0/CVE-2023-48795 PoC on GitHub
oseasfr/Scanner_CVE_OpenSSH PoC on GitHub

Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.

Patch, vendor advisory and mitigation references on NVD 26

Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.

Change history 1

2026-10-15 01:48First seenCVSS 5.9 · openbsd, putty, filezilla-projectNVD modified 2026-10-15 01:17

Affected (CPE criteria) 74

cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:*
cpe:2.3:a:putty:putty:*:*:*:*:*:*:*:*
cpe:2.3:a:filezilla-project:filezilla_client:*:*:*:*:*:*:*:*
cpe:2.3:a:panic:transmit_5:*:*:*:*:*:*:*:*
cpe:2.3:a:panic:nova:*:*:*:*:*:*:*:*
cpe:2.3:a:roumenpetrov:pkixssh:*:*:*:*:*:*:*:*
cpe:2.3:a:winscp:winscp:*:*:*:*:*:*:*:*
cpe:2.3:a:bitvise:ssh_client:*:*:*:*:*:*:*:*
cpe:2.3:a:bitvise:ssh_server:*:*:*:*:*:*:*:*
cpe:2.3:o:lancom-systems:lcos:*:*:*:*:*:*:*:*
cpe:2.3:o:lancom-systems:lcos_fx:-:*:*:*:*:*:*:*
cpe:2.3:o:lancom-systems:lcos_lx:-:*:*:*:*:*:*:*
cpe:2.3:o:lancom-systems:lcos_sx:4.20:*:*:*:*:*:*:*
cpe:2.3:o:lancom-systems:lcos_sx:5.20:*:*:*:*:*:*:*
cpe:2.3:o:lancom-systems:lanconfig:-:*:*:*:*:*:*:*
cpe:2.3:a:vandyke:securecrt:*:*:*:*:*:*:*:*
cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:*
cpe:2.3:a:net-ssh:net-ssh:7.2.0:*:*:*:*:ruby:*:*
cpe:2.3:a:ssh2_project:ssh2:*:*:*:*:*:node.js:*:*
cpe:2.3:a:proftpd:proftpd:*:*:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:*
cpe:2.3:a:crates:thrussh:*:*:*:*:*:*:*:*
cpe:2.3:a:tera_term_project:tera_term:*:*:*:*:*:*:*:*
cpe:2.3:a:oryx-embedded:cyclone_ssh:*:*:*:*:*:*:*:*
cpe:2.3:a:crushftp:crushftp:*:*:*:*:*:*:*:*
cpe:2.3:a:netsarang:xshell_7:*:*:*:*:*:*:*:*
cpe:2.3:a:paramiko:paramiko:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openstack_platform:16.1:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openstack_platform:16.2:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openstack_platform:17.1:*:*:*:*:*:*:*
cpe:2.3:a:redhat:ceph_storage:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_serverless:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_gitops:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_pipelines:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_developer_tools_and_services:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_data_foundation:4.0:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_api_for_data_protection:-:*:*:*:*:*:*:*
and 34 more

References 150

http://packetstormsecurity.com/files/176280/Terrapin-SSH-Connection-Weakening.html Third Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2024/Mar/21 Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/12/18/3 Mailing List
http://www.openwall.com/lists/oss-security/2023/12/19/5 Mailing List
http://www.openwall.com/lists/oss-security/2023/12/20/3 Mailing List, Mitigation
http://www.openwall.com/lists/oss-security/2024/03/06/3 Mailing List
http://www.openwall.com/lists/oss-security/2024/04/17/8 Mailing List
https://access.redhat.com/security/cve/cve-2023-48795 Third Party Advisory
https://arstechnica.com/security/2023/12/hackers-can-break-ssh-channel-integrity-using-novel-data-corruption-attack/ Press/Media Coverage
https://bugs.gentoo.org/920280 Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2254210 Issue Tracking
https://bugzilla.suse.com/show_bug.cgi?id=1217950 Issue Tracking
https://crates.io/crates/thrussh/versions Release Notes
https://filezilla-project.org/versions.php Release Notes
https://forum.netgate.com/topic/184941/terrapin-ssh-attack Issue Tracking
https://git.libssh.org/projects/libssh.git/commit/?h=stable-0.10&id=10e09e273f69e149389b3e0e5d44b8c221c2e7f6 Patch
https://github.com/NixOS/nixpkgs/pull/275249 Release Notes
https://github.com/PowerShell/Win32-OpenSSH/issues/2189 Issue Tracking
https://github.com/PowerShell/Win32-OpenSSH/releases/tag/v9.5.0.0p1-Beta Release Notes
https://github.com/TeraTermProject/teraterm/commit/7279fbd6ef4d0c8bdd6a90af4ada2899d786eec0 Patch
https://github.com/TeraTermProject/teraterm/releases/tag/v5.1 Release Notes
https://github.com/advisories/GHSA-45x7-px36-x8w8 Third Party Advisory
https://github.com/apache/mina-sshd/issues/445 Issue Tracking
https://github.com/connectbot/sshlib/commit/5c8b534f6e97db7ac0e0e579331213aa25c173ab Patch
https://github.com/connectbot/sshlib/compare/2.2.21...2.2.22 Third Party Advisory
https://github.com/cyd01/KiTTY/issues/520 Issue Tracking
https://github.com/drakkan/sftpgo/releases/tag/v2.5.6 Release Notes
https://github.com/erlang/otp/blob/d1b43dc0f1361d2ad67601169e90a7fc50bb0369/lib/ssh/doc/src/notes.xml#L39-L42 Patch
https://github.com/erlang/otp/releases/tag/OTP-26.2.1 Release Notes
https://github.com/golang/crypto/commit/9d2ee975ef9fe627bf0a6f01c1f69e8ef1d4f05d Patch
https://github.com/hierynomus/sshj/issues/916 Issue Tracking
https://github.com/janmojzis/tinyssh/issues/81 Issue Tracking
https://github.com/jtesta/ssh-audit/commit/8e972c5e94b460379fe0c7d20209c16df81538a5 Patch
https://github.com/libssh2/libssh2/pull/1291 Mitigation
https://github.com/mkj/dropbear/blob/17657c36cce6df7716d5ff151ec09a665382d5dd/CHANGES#L25 Patch
https://github.com/mscdex/ssh2/commit/97b223f8891b96d6fc054df5ab1d5a1a545da2a3 Patch
https://github.com/mwiede/jsch/compare/jsch-0.2.14...jsch-0.2.15 Product
https://github.com/mwiede/jsch/issues/457 Issue Tracking
https://github.com/mwiede/jsch/pull/461 Release Notes
https://github.com/net-ssh/net-ssh/blob/2e65064a52d73396bfc3806c9196fc8108f33cd8/CHANGES.txt#L14-L16 Patch
https://github.com/openssh/openssh-portable/commits/master Patch
https://github.com/paramiko/paramiko/issues/2337 Issue Tracking
https://github.com/proftpd/proftpd/blob/0a7ea9b0ba9fcdf368374a226370d08f10397d99/RELEASE_NOTES Release Notes
https://github.com/proftpd/proftpd/blob/d21e7a2e47e9b38f709bec58e3fa711f759ad0e1/RELEASE_NOTES Release Notes
https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTES Release Notes
https://github.com/proftpd/proftpd/issues/456 Issue Tracking
https://github.com/rapier1/hpn-ssh/releases Release Notes
https://github.com/ronf/asyncssh/blob/develop/docs/changes.rst Release Notes
https://github.com/ronf/asyncssh/tags Release Notes
https://github.com/ssh-mitm/ssh-mitm/issues/165 Issue Tracking
https://github.com/warp-tech/russh/releases/tag/v0.40.2 Release Notes
https://gitlab.com/libssh/libssh-mirror/-/tags Release Notes
https://groups.google.com/g/golang-announce/c/-n5WqVC18LQ Mailing List
https://groups.google.com/g/golang-announce/c/qA3XtxvMUyg Mailing List
https://help.panic.com/releasenotes/transmit5/ Release Notes
https://jadaptive.com/important-java-ssh-security-update-new-ssh-vulnerability-discovered-cve-2023-48795/ Press/Media Coverage
https://lists.debian.org/debian-lts-announce/2023/12/msg00017.html Mailing List
https://lists.debian.org/debian-lts-announce/2024/01/msg00013.html Mailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/01/msg00014.html Mailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/04/msg00016.html Mailing List, Third Party Advisory