SB2025110530 - Ubuntu update for runc-app
Published: November 5, 2025 Updated: November 14, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) UNIX symbolic link following (CVE-ID: CVE-2025-31133)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a symlink following issue within the maskedPaths feature. A local user can create a specially crafted symbolic link to a critical file on the system and overwrite it with privileges of the application.
Successful exploitation of this vulnerability may result in privilege escalation.
2) UNIX symbolic link following (CVE-ID: CVE-2025-52565)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a symlink following issue related to /dev/console mounts. A local user can escape the container using a malicious config and escalate privileges on the system.
3) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2019-16884)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to incorrect checking of the mount targets in libcontainer/rootfs_linux.go in runc. A local user can bypass AppArmor restrictions and perform unauthorized actions on the system, as demonstrated by overwriting the /proc directory with a malicious Doker image.
4) UNIX symbolic link following (CVE-ID: CVE-2025-52881)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a symlink following issue related to procfs write redirects. A local user can create a specially crafted symbolic link to a critical file on the system and overwrite it with privileges of the application.
Successful exploitation of this vulnerability may result in privilege escalation.
Remediation
Install update from vendor's website.