UpHeron
All vulnerabilities

Servers and applications

CVE-2010-4344

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.

Actively exploited: CISA added it to its Known Exploited Vulnerabilities catalog on 25 Mar 2022.

Severity
Critical 9.8
Published
14 Dec 2010
Last changed
16 Jun 2026
Added to UpHeron
1 Nov 2026
Fixed in
4.70
Exploit chance
72% in the next 30 daysHigher than 99% of CVEs. EPSS by FIRST, 12 Nov 2026
Weakness
Out-of-bounds write (CWE-787)
Attack
Over the network · No login needed · No user action needed
Attacker can
Read data · Change data · Take it down
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Sources
NVD

Affected software

SoftwareAffected versions
EximServers and applications · cpe:a:exim:exim
  • Every version before 4.70

Known exploited

CISA name
Exim Heap-Based Buffer Overflow Vulnerability
Required action
Apply updates per vendor instructions.
Due for US agencies
15 Apr 2022
Used in ransomware
Not known

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2010-4344
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2010-4344