USN-7270-1: OpenSSH vulnerabilities
It was discovered that the OpenSSH client incorrectly handled the non-default VerifyHostKeyDNS option. If that option were enabled, an attacker could possibly impersonate a server by completely bypassing the server identity check. (CVE-2025-26465) It was discovered that OpenSSH incorrectly handled the transport-level ping facility. A remote attacker could possibly use this issue to cause OpenSSH clients and servers to consume resources, leading to a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 24.10. (CVE-2025-26466)
Affected Software
Event History
Frequently Asked Questions
What is the vulnerability associated with USN-7270-1?
USN-7270-1 describes a security issue in OpenSSH where attackers could impersonate a server due to improper handling of the VerifyHostKeyDNS option.
How do I fix the vulnerability listed in USN-7270-1?
To fix the vulnerability in USN-7270-1, update your OpenSSH packages to the recommended versions: 1:9.7p1-7ubuntu4.2 for Ubuntu 24.10, 1:9.6p1-3ubuntu13.8 for Ubuntu 24.04, and 1:8.9p1-3ubuntu0.11 for Ubuntu 22.04.
What are the affected versions in USN-7270-1?
Affected versions include OpenSSH client and server versions before 1:9.7p1-7ubuntu4.2, 1:9.6p1-3ubuntu13.8, and 1:8.9p1-3ubuntu0.11 based on your Ubuntu release.
Who is responsible for discovering the USN-7270-1 vulnerability?
The vulnerability described in USN-7270-1 was discovered by the security research community, specifically relating to OpenSSH's handling of DNS-based server verification.
Is USN-7270-1 a critical vulnerability?
Yes, the vulnerability in USN-7270-1 is critical as it allows attackers to bypass server identity checks, potentially leading to man-in-the-middle attacks.