PatchTheCVECVE-2020-8833: Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a
CVE-2020-8833 is a medium-severity flaw (CVSS 5.6) affecting ubuntu linux, apport. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Public exploit reference
- On your watchlist
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 5.6 (Medium) |
| Attack vector | Local |
| Attack complexity | High |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 72%) |
| CISA exploited list | No |
| Weakness | CWE-367 |
| Published | 2020-04-22 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2020-8833?
ubuntu linux: mitigate or apply the listed mitigation; apport: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2020-8833 being exploited?
CVE-2020-8833 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2020-8833 affect?
CVE-2020-8833 affects ubuntu linux, apport. Severity is medium (CVSS 5.6). 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
How urgent is CVE-2020-8833?
Priority 37/100. Public exploit reference; On your watchlist
Software pages
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