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CVE-2023-48795

MEDIUMCVSS 5.9/10EPSS 94.07%

Last modified

CVE-2023-48795 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. 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. EPSS estimates a 94.07% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability
94.07%

99.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
OpenbsdOpenssh< 9.6
PuttyPutty< 0.80
Filezilla-ProjectFilezilla Client< 3.66.4
PanicTransmit 5< 5.10.4
PanicNova< 11.8
RoumenpetrovPkixssh< 14.4
WinscpWinscp< 6.2.2
BitviseSsh Client< 9.33
BitviseSsh Server< 9.32
Lancom-SystemsLcos<= 3.66.4
Lancom-SystemsLcos FxAll versions
Lancom-SystemsLcos LxAll versions
Lancom-SystemsLcos Sx4.20
Lancom-SystemsLcos Sx5.20
Lancom-SystemsLanconfigAll versions
VandykeSecurecrt< 9.4.3
LibsshLibssh< 0.10.6
Net-SshNet-Ssh7.2.0
Ssh2 ProjectSsh2<= 1.11.0
ProftpdProftpd<= 1.3.8b
FreebsdFreebsd<= 12.4
CratesThrussh< 0.35.1
Tera Term ProjectTera Term<= 5.1
Oryx-EmbeddedCyclone Ssh< 2.3.4
CrushftpCrushftp<= 10.6.0
NetsarangXshell 7< build__0144
ParamikoParamiko< 3.4.0
RedhatOpenshift Container Platform4.0
RedhatOpenstack Platform16.1
RedhatOpenstack Platform16.2
RedhatOpenstack Platform17.1
RedhatCeph Storage6.0
RedhatEnterprise Linux8.0
RedhatEnterprise Linux9.0
RedhatOpenshift ServerlessAll versions
RedhatOpenshift GitopsAll versions
RedhatOpenshift PipelinesAll versions
RedhatOpenshift Developer Tools And ServicesAll versions
RedhatOpenshift Data Foundation4.0
RedhatOpenshift Api For Data ProtectionAll versions
RedhatOpenshift Virtualization4
RedhatStorage3.0
RedhatDiscoveryAll versions
RedhatOpenshift Dev SpacesAll versions
RedhatCert-Manager Operator For Red Hat OpenshiftAll versions
RedhatKeycloakAll versions
RedhatJboss Enterprise Application Platform7.0
RedhatSingle Sign-On7.0
RedhatAdvanced Cluster Security3.0
RedhatAdvanced Cluster Security4.0

Showing 50 of 83 affected configurations. See NVD for the full list.

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-48795?
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.
How severe is CVE-2023-48795?
CVE-2023-48795 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 94.07% probability of exploitation in the next 30 days.
How do I fix CVE-2023-48795?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-48795?

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Source: NVD / NIST