SB2025021847 - Ubuntu update for openssh

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Main Vulnerability Database SB2025021847

SB2025021847 - Ubuntu update for openssh

Published: February 18, 2025 Updated: June 27, 2025

Security Bulletin ID SB2025021847
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Man-in-the-Middle (MitM) attack (CVE-ID: CVE-2025-26465)

CWE-ID: CWE-300 - Channel Accessible by Non-Endpoint ('Man-in-the-Middle')

CVSSv4: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to incorrect processing of user-supplied data in ssh(1). A remote attacker can perform server impersonation when VerifyHostKeyDNS enabled.


2) Input validation error (CVE-ID: CVE-2025-26466)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Green


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input related to SSH2_MSG_PING handling in sshd(8). A remote attacker can send specially crafted packets to the server and perform a denial of service (DoS) attack.


Remediation

Install update from vendor's website.

References