# CVE-2010-4344: Exim Heap-Based Buffer Overflow Vulnerability

> CVE-2010-4344: Exim Heap-Based Buffer Overflow Vulnerability. CVSS 9.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2010-4344
Last updated: 2025-10-22T00:05:50Z

- Published: 2010-12-14 15:00 UTC · Updated: 2025-10-22 00:05 UTC · Assigner: redhat
- CVSS: 9.8 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 71.7%, 99th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2022-03-25, federal due date 2022-04-15, ransomware use: Unknown

## 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.

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Exim: Exim

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2010-4344)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2010-4344)
- [http://atmail.com/blog/2010/atmail-6204-now-available/](http://atmail.com/blog/2010/atmail-6204-now-available/)
- [http://bugs.exim.org/show\_bug.cgi?id=787](http://bugs.exim.org/show_bug.cgi?id=787)
- [http://git.exim.org/exim.git/commit/24c929a27415c7cfc7126c47e4cad39acf3efa6b](http://git.exim.org/exim.git/commit/24c929a27415c7cfc7126c47e4cad39acf3efa6b)
- [http://lists.exim.org/lurker/message/20101210.164935.385e04d0.en.html](http://lists.exim.org/lurker/message/20101210.164935.385e04d0.en.html)
- [http://lists.opensuse.org/opensuse-security-announce/2010-12/msg00003.html](http://lists.opensuse.org/opensuse-security-announce/2010-12/msg00003.html)
- [http://openwall.com/lists/oss-security/2010/12/10/1](http://openwall.com/lists/oss-security/2010/12/10/1)
- [https://bugzilla.redhat.com/show\_bug.cgi?id=661756](https://bugzilla.redhat.com/show_bug.cgi?id=661756)
- [http://secunia.com/advisories/40019](http://secunia.com/advisories/40019)
- [http://secunia.com/advisories/42576](http://secunia.com/advisories/42576)
- [http://secunia.com/advisories/42586](http://secunia.com/advisories/42586)
- [http://secunia.com/advisories/42587](http://secunia.com/advisories/42587)
- [http://secunia.com/advisories/42589](http://secunia.com/advisories/42589)
- [http://www.cpanel.net/2010/12/exim-remote-memory-corruption-vulnerability-notification-cve-2010-4344.html](http://www.cpanel.net/2010/12/exim-remote-memory-corruption-vulnerability-notification-cve-2010-4344.html)
- [http://www.debian.org/security/2010/dsa-2131](http://www.debian.org/security/2010/dsa-2131)
- [http://www.exim.org/lurker/message/20101207.215955.bb32d4f2.en.html](http://www.exim.org/lurker/message/20101207.215955.bb32d4f2.en.html)
- [http://www.kb.cert.org/vuls/id/682457](http://www.kb.cert.org/vuls/id/682457)
- [http://www.metasploit.com/modules/exploit/unix/smtp/exim4\_string\_format](http://www.metasploit.com/modules/exploit/unix/smtp/exim4_string_format)
- [http://www.openwall.com/lists/oss-security/2021/05/04/7](http://www.openwall.com/lists/oss-security/2021/05/04/7)
- [http://www.osvdb.org/69685](http://www.osvdb.org/69685)
- [http://www.redhat.com/support/errata/RHSA-2010-0970.html](http://www.redhat.com/support/errata/RHSA-2010-0970.html)
- [http://www.securityfocus.com/archive/1/515172/100/0/threaded](http://www.securityfocus.com/archive/1/515172/100/0/threaded)
- [http://www.securityfocus.com/bid/45308](http://www.securityfocus.com/bid/45308)
- [http://www.securitytracker.com/id?1024858](http://www.securitytracker.com/id?1024858)
- [http://www.theregister.co.uk/2010/12/11/exim\_code\_execution\_peril/](http://www.theregister.co.uk/2010/12/11/exim_code_execution_peril/)
- [http://www.ubuntu.com/usn/USN-1032-1](http://www.ubuntu.com/usn/USN-1032-1)
- [http://www.vupen.com/english/advisories/2010/3171](http://www.vupen.com/english/advisories/2010/3171)
- [http://www.vupen.com/english/advisories/2010/3172](http://www.vupen.com/english/advisories/2010/3172)
- [http://www.vupen.com/english/advisories/2010/3181](http://www.vupen.com/english/advisories/2010/3181)
- [http://www.vupen.com/english/advisories/2010/3186](http://www.vupen.com/english/advisories/2010/3186)
- [http://www.vupen.com/english/advisories/2010/3204](http://www.vupen.com/english/advisories/2010/3204)
- [http://www.vupen.com/english/advisories/2010/3246](http://www.vupen.com/english/advisories/2010/3246)
- [http://www.vupen.com/english/advisories/2010/3317](http://www.vupen.com/english/advisories/2010/3317)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2010-4344 · Markdown: https://rewindex.com/cve/CVE-2010-4344.md · JSON: https://rewindex.com/api/v1/cves/CVE-2010-4344 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T01:59:15.839Z