CVE-2010-4344

Name: CVE-2010-4344
Creator: NVD / NIST
Published: 2010-12-14T16:00:04.163+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10Actively ExploitedEPSS 71.79%

Last modified Jun 16, 2026

CVE-2010-4344 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 71.79% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

71.79%

99.3th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Apr 15, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Exim	Exim	< 4.70
Opensuse	Opensuse	11.1
Opensuse	Opensuse	11.2
Opensuse	Opensuse	11.3
Debian	Debian Linux	5.0
Canonical	Ubuntu Linux	6.06
Canonical	Ubuntu Linux	8.04
Canonical	Ubuntu Linux	9.10

References

ftp://ftp.exim.org/pub/exim/ChangeLogs/ChangeLog-4.70Broken Link
http://atmail.com/blog/2010/atmail-6204-now-available/Broken Link
http://bugs.exim.org/show_bug.cgi?id=787Issue Tracking, Patch
http://git.exim.org/exim.git/commit/24c929a27415c7cfc7126c47e4cad39acf3efa6bMailing List, Patch
http://lists.exim.org/lurker/message/20101210.164935.385e04d0.en.htmlMailing List, Patch
http://lists.opensuse.org/opensuse-security-announce/2010-12/msg00003.htmlMailing List, Third Party Advisory
http://openwall.com/lists/oss-security/2010/12/10/1Mailing List, Third Party Advisory
http://secunia.com/advisories/40019Broken Link, Vendor Advisory
http://secunia.com/advisories/42576Broken Link, Vendor Advisory
http://secunia.com/advisories/42586Broken Link, Vendor Advisory
http://secunia.com/advisories/42587Broken Link, Vendor Advisory
http://secunia.com/advisories/42589Broken Link, Vendor Advisory
http://www.cpanel.net/2010/12/exim-remote-memory-corruption-vulnerability-notification-cve-2010-4344.htmlBroken Link
http://www.debian.org/security/2010/dsa-2131Mailing List, Third Party Advisory
http://www.exim.org/lurker/message/20101207.215955.bb32d4f2.en.htmlExploit, Mailing List
http://www.kb.cert.org/vuls/id/682457Third Party Advisory, US Government Resource
http://www.metasploit.com/modules/exploit/unix/smtp/exim4_string_formatThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/04/7Exploit, Mailing List
http://www.osvdb.org/69685Broken Link, Exploit, Patch
http://www.redhat.com/support/errata/RHSA-2010-0970.htmlBroken Link
http://www.securityfocus.com/archive/1/515172/100/0/threadedBroken Link, Third Party Advisory, VDB Entry
http://www.securityfocus.com/bid/45308Broken Link, Third Party Advisory, VDB Entry
http://www.securitytracker.com/id?1024858Broken Link, Third Party Advisory, VDB Entry
http://www.theregister.co.uk/2010/12/11/exim_code_execution_peril/Press/Media Coverage
http://www.ubuntu.com/usn/USN-1032-1Third Party Advisory
http://www.vupen.com/english/advisories/2010/3171Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3172Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3181Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3186Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3204Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3246Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3317Broken Link
https://bugzilla.redhat.com/show_bug.cgi?id=661756Exploit, Issue Tracking
ftp://ftp.exim.org/pub/exim/ChangeLogs/ChangeLog-4.70Broken Link
http://atmail.com/blog/2010/atmail-6204-now-available/Broken Link
http://bugs.exim.org/show_bug.cgi?id=787Issue Tracking, Patch
http://git.exim.org/exim.git/commit/24c929a27415c7cfc7126c47e4cad39acf3efa6bMailing List, Patch
http://lists.exim.org/lurker/message/20101210.164935.385e04d0.en.htmlMailing List, Patch
http://lists.opensuse.org/opensuse-security-announce/2010-12/msg00003.htmlMailing List, Third Party Advisory
http://openwall.com/lists/oss-security/2010/12/10/1Mailing List, Third Party Advisory
http://secunia.com/advisories/40019Broken Link, Vendor Advisory
http://secunia.com/advisories/42576Broken Link, Vendor Advisory
http://secunia.com/advisories/42586Broken Link, Vendor Advisory
http://secunia.com/advisories/42587Broken Link, Vendor Advisory
http://secunia.com/advisories/42589Broken Link, Vendor Advisory
http://www.cpanel.net/2010/12/exim-remote-memory-corruption-vulnerability-notification-cve-2010-4344.htmlBroken Link
http://www.debian.org/security/2010/dsa-2131Mailing List, Third Party Advisory
http://www.exim.org/lurker/message/20101207.215955.bb32d4f2.en.htmlExploit, Mailing List
http://www.kb.cert.org/vuls/id/682457Third Party Advisory, US Government Resource
http://www.metasploit.com/modules/exploit/unix/smtp/exim4_string_formatThird Party Advisory
http://www.openwall.com/lists/oss-security/2021/05/04/7Exploit, Mailing List
http://www.osvdb.org/69685Broken Link, Exploit, Patch
http://www.redhat.com/support/errata/RHSA-2010-0970.htmlBroken Link
http://www.securityfocus.com/archive/1/515172/100/0/threadedBroken Link, Third Party Advisory, VDB Entry
http://www.securityfocus.com/bid/45308Broken Link, Third Party Advisory, VDB Entry
http://www.securitytracker.com/id?1024858Broken Link, Third Party Advisory, VDB Entry
http://www.theregister.co.uk/2010/12/11/exim_code_execution_peril/Press/Media Coverage
http://www.ubuntu.com/usn/USN-1032-1Third Party Advisory
http://www.vupen.com/english/advisories/2010/3171Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3172Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3181Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3186Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3204Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3246Broken Link, Vendor Advisory
http://www.vupen.com/english/advisories/2010/3317Broken Link
https://bugzilla.redhat.com/show_bug.cgi?id=661756Exploit, Issue Tracking
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2010-4344US Government Resource

Timeline

Published: Dec 14, 2010
Last Modified: Jun 16, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2010-4344?

How severe is CVE-2010-4344?

CVE-2010-4344 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 71.79% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2010-4344?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2010-4344?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST