Which products and versions are affected by CVE-2010-4344?

Affected: Exim; Ubuntu Linux (Canonical) versions 6.06, 8.04, 9.10; Debian Linux versions 5.0, among others. The full list is in the CVE brief.

Is CVE-2010-4344 being exploited in the wild?

It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Dec 10, 2010.

Is CVE-2010-4344 in the CISA KEV catalog?

Yes. It was added on Mar 25, 2022 with a federal remediation due date of Apr 15, 2022.

Is there a public exploit for CVE-2010-4344?

Public exploit code is available.

Is there a fix for CVE-2010-4344?

Fixed versions are available, including Exim 0:4.43-1.RHEL4.5.el4_8.1, Exim 0:4.63-3.el5_4.1, Exim 4.63-5.el5_5.2.

How urgently should CVE-2010-4344 be patched?

Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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Vulnerability Intelligence

CVE-2010-4344

CriticalExploitedPublic exploit

Heap-based buffer overflow in the string_vformat function in string.c in Exim before 4.70 allows remote attackers to execute arbitrary code via an SMTP session that includes two MAIL commands in conjunction with a large message containing crafted headers, leading to improper…

Published May 5, 2021 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2010-4344, DSA-2131-1, TR-21-0383

Key Facts

Patch immediately

CVE-2010-4344 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Exim, Ubuntu Linux (Canonical), Debian Linux and 6 more products.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Dec 10, 2010. Public exploit code is available.
EPSS estimates a 72% probability of exploitation in the next 30 days.
Fixed versions are available, including Exim 0:4.43-1.RHEL4.5.el4_8.1, Exim 0:4.63-3.el5_4.1, Exim 4.63-5.el5_5.2.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v3.1

9.8

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

EPSS (30-day exploit likelihood)

72%

Higher than 99.4% of all scored CVEs

Exploited in the wild

Yes

4 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2010-4344 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

Known-Exploited Catalog Listings

Catalog	Added	Remediation due	Ransomware use
CISA KEV	Mar 25, 2022	Apr 15, 2022	Not reported
Industry KEV feed	Dec 10, 2010	Apr 15, 2022	Not reported
CIRCL KEV	Mar 25, 2022	Apr 15, 2022	Not reported
ENISA EUVD	Mar 25, 2022	n/a	Not reported

Required action: Apply updates per vendor instructions.

Affected Products

27 affected entries in total

Product	Affected versions	Fixed in
EximExim	See advisory	4.70
Ubuntu LinuxCanonical	6.06, 8.04, 9.10	n/a
Debian LinuxDebian	5.0	n/a
OpensuseOpensuse	11.1, 11.2, 11.3	n/a
exim4debian	See advisory	4.70-1

4 more affected products in the full CVE brief

Patched Releases

Exim

0:4.43-1.RHEL4.5.el4_8.1, 0:4.63-3.el5_4.1, 4.63-5.el5_5.2, 4.86.2-2.2, 4.70

exim-mon

4.63-5.el5_5.2

exim-sa

4.63-5.el5_5.2

exim4

4.69-9+lenny1, 4.70-1

eximon

4.86.2-2.2

eximstats-html

4.86.2-2.2

Timeline

Added to Industry KEV feed
Dec 10, 2010
Publicly disclosed
May 5, 2021
Added to CISA KEV
Mar 25, 2022
Added to CIRCL KEV
Mar 25, 2022
Added to ENISA EUVD
Mar 25, 2022
Last updated
Aug 4, 2026

Weakness Type

CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-787 Out-of-bounds Write

References

15 more references in the full CVE brief

FAQ

Common Questions.

Heap-based buffer overflow in the string_vformat function in string.c in Exim before 4.70 allows remote attackers to execute arbitrary code via an SMTP session that includes two MAIL commands in conjunction with a large message containing crafted headers, leading to improper rejection logging.
Affected: Exim; Ubuntu Linux (Canonical) versions 6.06, 8.04, 9.10; Debian Linux versions 5.0, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Dec 10, 2010.
Yes. It was added on Mar 25, 2022 with a federal remediation due date of Apr 15, 2022.
Public exploit code is available.
Fixed versions are available, including Exim 0:4.43-1.RHEL4.5.el4_8.1, Exim 0:4.63-3.el5_4.1, Exim 4.63-5.el5_5.2.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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