CVE-2021-38371: exim Injection
CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2021-38371USN-6881-1DEBIAN-CVE-2021-38371
Published 10-08-2021Last modified 03-11-2025
Vulnerability summary
CVE-2021-38371 is a high (CVSS 7.5) Injection vulnerability in exim. EPSS estimates a 2.00% chance of exploitation in the next 30 days, higher than 80.4% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (NVD)EPSS score
2.00%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 1Timeline
- 10-08-2021PublishedVulnerability first disclosed.
- 03-11-2025Last modifiedVulnerability information updated.
Description
The STARTTLS feature in Exim through 4.94.2 allows response injection (buffering) during MTA SMTP sending.
CVSS metrics
4 scores · 3 sources · 2 versionsHigh 7.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Medium 5.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:N/I:P/A:NSourcesSingle source
EPSS trend
Probability
2.00%
Chance of exploitation in the next 30 days
Percentile
80%
Versus all other CVEs
30-day change
0.00 pp
From 2.00% on 20-09-2026
20-09-202620-10-2026
EPSS score2.00%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- exim4< 4.95~RC2-1
Exim1 product
- exim≤ 4.94.2
Ubuntu1 product
- exim4< 4.82-3ubuntu2.4+esm8 | < 4.86.2-2ubuntu2.6+esm7 | < 4.90.1-1ubuntu1.10+esm4 | < 4.93-13ubuntu1.11
3 vendors · 3 products
