CVE-2020-8833
Apport race condition in crash report permissions
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu22
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Canonical Apport
From 2.20.1 · fixed in 2.20.1-0ubuntu2.23; From 2.20.9 · fixed in 2.20.9-0ubuntu7.14; From 2.20.11 · fixed in 2.20.11-0ubuntu22