SSH Terrapin Prefix Truncation Weakness (CVE-2023-48795)

medium Nessus Plugin ID 187315


The remote SSH server is vulnerable to a mitm prefix truncation attack.


The remote SSH server is vulnerable to a man-in-the-middle prefix truncation weakness known as Terrapin. This can allow a remote, man-in-the-middle attacker to bypass integrity checks and downgrade the connection's security.

Note that this plugin only checks for remote SSH servers that support either ChaCha20-Poly1305 or CBC with Encrypt-then-MAC and do not support the strict key exchange countermeasures. It does not check for vulnerable software versions.


Contact the vendor for an update with the strict key exchange countermeasures or disable the affected algorithms.

See Also

Plugin Details

Severity: Medium

ID: 187315

File Name: ssh_terrapin_weakness.nasl

Version: 1.4

Type: remote

Family: Misc.

Published: 12/27/2023

Updated: 1/29/2024

Supported Sensors: Nessus

Risk Information


Risk Factor: Medium

Score: 6.7


Risk Factor: Medium

Base Score: 5.4

Temporal Score: 4.2

Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:C/A:N

CVSS Score Source: CVE-2023-48795


Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.3

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:openbsd:openssh

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 12/18/2023

Vulnerability Publication Date: 12/18/2023

Reference Information

CVE: CVE-2023-48795