CVE-2020-8833
Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a possible privilege escalation opportunity.
Does this matter?
Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 4.7 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.34% probability · 28th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Affected
- canonical/ubuntu linux · apport project/apport
- Source
- security@ubuntu.com
References
- https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933Exploit, 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/1862933Exploit, Third Party Advisory
- https://usn.ubuntu.com/4315-1/Third Party Advisory
- https://usn.ubuntu.com/4315-2/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.