Ubuntu update for ovn

1) Security features bypass

EUVDB-ID: #VU103659

Risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:L/E:U/U:Green]

CVE-ID: CVE-2025-0650

CWE-ID: CWE-254 - Security Features

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to improper handling of UDP packets. A remote attacker can send specially crafted UDP packets that bypass egress access control lists (ACLs) in OVN installations and gain unauthorized access to virtual machines and containers running on the OVN network.

Successful exploitation of the vulnerability requires that ACLs on OVN installations are configured with a logical switch with DNS records set on it and if the same switch has any egress ACLs configured.

Mitigation

Update the affected package ovn to the latest version.

Vulnerable software versions

Ubuntu: 20.04 - 24.10

ovn-ic (Ubuntu package): before 20.03.2-0ubuntu0.20.04.6

ovn-host (Ubuntu package): before 20.03.2-0ubuntu0.20.04.6

ovn-docker (Ubuntu package): before 20.03.2-0ubuntu0.20.04.6

ovn-common (Ubuntu package): before 20.03.2-0ubuntu0.20.04.6

ovn-central (Ubuntu package): before 20.03.2-0ubuntu0.20.04.6

CPE2.3

• cpe:2.3:o:canonical:ubuntu:20.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:22.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:24.04:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu:24.10:*:*:*:*:*:*:*
• cpe:2.3:a:canonical:ovn-ic:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:a:canonical:ovn-host_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:a:canonical:ovn-docker_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:a:canonical:ovn-common_ubuntu_package:*:*:*:*:*:ubuntu:*:*
• cpe:2.3:a:canonical:ovn-central_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-7396-1

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.