Is CVE-2021-38371 in the CISA KEV catalog?

No. CVE-2021-38371 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-38371?

CVE-2021-38371 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-38371?

CVE-2021-38371 has an EPSS score of 2.00% (78th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-38371?

Upgrade exim4 on debian 11 to 4.94.2-7+deb11u4 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2021-38371

HIGHEPSS 78th pctl

7.5

CVSS v3

NVD

Description

The STARTTLS feature in Exim through 4.94.2 allows response injection (buffering) during MTA SMTP sending.

CWE-74Injection

How to fix

Remediation Available

exim4Debian

Fixed in:4.94.2-7+deb11u4CVE-2021-38371

Fixed in:4.95~RC2-1CVE-2021-38371

exim4Ubuntu

Fixed in:4.82-3ubuntu2.4+esm8USN-6881-1

Fixed in:4.86.2-2ubuntu2.6+esm7USN-6881-1

Fixed in:4.90.1-1ubuntu1.10+esm4USN-6881-1

Fixed in:4.93-13ubuntu1.11USN-6881-1

exim4-baseUbuntu

Fixed in:4.82-3ubuntu2.4+esm8USN-6881-1

Fixed in:4.86.2-2ubuntu2.6+esm7USN-6881-1

Fixed in:4.90.1-1ubuntu1.10+esm4USN-6881-1

Fixed in:4.93-13ubuntu1.11USN-6881-1

eximon4Ubuntu

Fixed in:4.82-3ubuntu2.4+esm8USN-6881-1

Fixed in:4.86.2-2ubuntu2.6+esm7USN-6881-1

Fixed in:4.90.1-1ubuntu1.10+esm4USN-6881-1

Fixed in:4.93-13ubuntu1.11USN-6881-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploit Intelligence

2.00%probability of exploitation in 30 days

78thpercentile

Elevated risk: more likely to be exploited than 78% of all known CVEs.

References

Vendor Advisory1

exim.org

Product1

exim.org

Other references2

Related Vulnerabilities

Other CWE-74 (Injection) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2013-2251	Critical	9.8	100%	KEV	Fix
CVE-2023-22527	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2019-2725	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2022-46169	Critical	9.8	100%	KEV	Fix
CVE-2022-35914	Critical	9.8	100%	KEV	-
CVE-2019-17558	High	7.5	99%	KEV	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-03.