Ubuntu update for libcap2

1) Input validation error

EUVDB-ID: #VU104166

Risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-1390

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a local user to bypass implemented security restrictions.

The vulnerability exists due to insufficient validation of user-supplied input when parsing groups names. The PAM module pam_cap.so of libcap configuration supports group names starting with “@”, during actual parsing, configurations not starting with “@” are incorrectly recognized as group names. A local user can use this vulnerability to escalate privileges on systems where "/etc/security/capability.conf" is used to configure user inherited privileges by constructing specific usernames.

Mitigation

Update the affected package libcap2 to the latest version.

Vulnerable software versions

Ubuntu: 20.04 - 24.10

libpam-cap (Ubuntu package): before 1:2.32-1ubuntu0.2

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:o:canonical:libpam-cap_ubuntu_package:*:*:*:*:*:ubuntu:*:*

External links

https://ubuntu.com/security/notices/USN-7287-1

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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