CVE-2021-3899 json
There is a race condition in the 'replaced executable' detection that, with the correct local configuration, allow an attacker to execute a…
published 2024-06-03 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27131
- cvss
- 7.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 32%
- public exploits
- 0
- none known
Summary
There is a race condition in the 'replaced executable' detection that, with the correct local configuration, allow an attacker to execute arbitrary code as root.
Patch / fix
- Canonical Ltd. Apport 2.21.0
- apport apport 2.21.0
- apport Ubuntu 18.04 LTS 2.20.9-0ubuntu7.28
- apport Ubuntu 20.04 LTS 2.20.11-0ubuntu27.24
- apport Ubuntu 22.04 LTS 2.20.11-0ubuntu82.1
- apport Ubuntu Pro 16.04 LTS 2.20.1-0ubuntu2.30+esm4
ubuntu advisories UBUNTU-CVE-2021-3899
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 2 y ago
Exploit prediction
0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CNA | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Canonical Ltd. Apport
- apport apport
Classification
- Weakness
-
- CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
References
-
bugs.launchpad.net
/ubuntu/+source/apport/+bug/1948376
issue-tracking, patch
-
ubuntu.com
/security/notices/USN-5427-1
vendor-advisory
-
cve.org
/CVERecord?id=CVE-2021-3899
issue-tracking, third-party-advisory
Sources
- CVE List CVE-2021-3899
- NVD CVE-2021-3899
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.