CVE-2020-8831
CWE-379Published: April 22, 2020· Updated: Jun 17, 2026
Official Description
Apport creates a world writable lock file with root ownership in the world writable /var/lock/apport directory. If the apport/ directory does not exist (this is not uncommon as /var/lock is a tmpfs), it will create the directory, otherwise it will simply continue execution using the existing directory. This allows for a symlink attack if an attacker were to create a symlink at /var/lock/apport, changing apport's lock file location. This file could then be used to escalate privileges, for example. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.
Technical Analysis
CVE-2020-8831 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 5.5.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (6)
Quick Facts
Related CVEs (CWE-379)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-8831 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts