{"id":"CVE-2020-8831","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-8831","generatedAt":"2026-10-27T22:33:02.889Z","title":"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.","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.","published":"2020-04-22T22:15:13.000Z","lastModified":"2026-06-17T03:27:01.000Z","status":"Modified","sourceIdentifier":"security@ubuntu.com","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"},"cwe":["CWE-379","CWE-59"],"affected":["canonical/ubuntu linux","apport project/apport"],"epss":{"score":0.00651,"percentile":0.50913,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.65%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://launchpad.net/bugs/1862348","tags":["Exploit","Third Party Advisory"],"source":"security@ubuntu.com"},{"url":"https://usn.ubuntu.com/4315-1/","tags":["Third Party Advisory"],"source":"security@ubuntu.com"},{"url":"https://usn.ubuntu.com/4315-2/","tags":["Third Party Advisory"],"source":"security@ubuntu.com"},{"url":"https://launchpad.net/bugs/1862348","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/4315-1/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://usn.ubuntu.com/4315-2/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-8831","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}