CVEvulnerability
CVE-2020-8833
4.7 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2020-04-22
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.6 MEDIUM — CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
- CVSS 3.1 ([email protected])
- 4.7 MEDIUM — CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
- CVSS 2.0 ([email protected])
- 1.9 LOW — AV:L/AC:M/Au:N/C:P/I:N/A:N
- Weaknesses
- CWE-367
Description
Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a possible privilege escalation opportunity. If fs.protected_symlinks is disabled, this can be exploited between the os.open and os.chown calls when the Apport cron script clears out crash files of size 0. A symlink with the same name as the deleted file can then be created upon which chown will be called, changing the file owner to root. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.
Affected configurations
• canonical ubuntu linux 14.04
• canonical ubuntu linux 16.04
• canonical ubuntu linux 18.04
• canonical ubuntu linux 19.10
• apport project apport
Related
Weakness · CWE (1)
- CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition weakness
References
- https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933 Exploit, Third Party Advisory
- https://usn.ubuntu.com/4315-1/ Third Party Advisory
- https://usn.ubuntu.com/4315-2/ Third Party Advisory
- https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933 Exploit, Third Party Advisory
- https://usn.ubuntu.com/4315-1/ Third Party Advisory
- https://usn.ubuntu.com/4315-2/ Third Party Advisory