CVE-2021-38371 json
The STARTTLS feature in Exim through 4.94.2 allows response injection (buffering) during MTA SMTP sending.
published 2021-08-10 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-24824
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.0%
- EPSS 2.0% chance of exploitation in 30 days, percentile 80%
- public exploits
- 0
- none known
Summary
The STARTTLS feature in Exim through 4.94.2 allows response injection (buffering) during MTA SMTP sending.
Patch / fix
- exim4 Debian 14, Debian 13, Debian 12 4.95~RC2-1
debian advisories DEBIAN-CVE-2021-38371
- exim4 Ubuntu 20.04 LTS 4.93-13ubuntu1.11
- exim4 Ubuntu Pro 14.04 LTS 4.82-3ubuntu2.4+esm8
- exim4 Ubuntu Pro 16.04 LTS 4.86.2-2ubuntu2.6+esm7
- exim4 Ubuntu Pro 18.04 LTS 4.90.1-1ubuntu1.10+esm4
ubuntu advisories UBUNTU-CVE-2021-38371
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
Exploit prediction
2.00% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
Classification
- Weakness
-
- CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component
References
-
exim.org
/static/doc/security/CVE-2021-38371.txt
broken-link, vendor-advisory
-
nostarttls.secvuln.info
tool-signature
-
exim.org
product
- lists.debian.org /debian-lts-announce/2024/10/msg00029.html
Sources
- CVE List CVE-2021-38371
- NVD CVE-2021-38371
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.