Vulnerability in Apport Project
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. 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.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (26.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Apport Project
- Canonical Apport — versions 2.20.1, 2.20.9, 2.20.11
- Canonical Ubuntu Linux — versions 14.04, 16.04, 18.04
Weakness classification (CWE)
Public proof-of-concept exploits
References
- usn.ubuntu.com/4315-1/ (Third Party Advisory)
- bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933 (Exploit, Third Party Advisory)
- usn.ubuntu.com/4315-2/ (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-8833?
- CVE-2020-8833 is a medium-severity vulnerability in Apport Project, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 5.6/10. Published 2020-04-22.
- How severe is CVE-2020-8833?
- Medium severity. CVSS v3 base score is 5.6 out of 10.
- Is CVE-2020-8833 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.