CVE-2003-0743: University Of Cambridge Exim

High severity, CVSS 7.5. EPSS: 5.7% chance of exploitation in the next 30 days.

Heap-based buffer overflow in smtp_in.c for Exim 3 (exim3) before 3.36 and Exim 4 (exim4) before 4.21 may allow remote attackers to execute arbitrary code via an invalid (1) HELO or (2) EHLO argument with a large number of spaces followed by a NULL character and a newline, which is not properly trimmed before the "(no argument given)" string is appended to the buffer.

Affected products

• University Of Cambridge Exim: version 3.0 only; version 3.3 only; version 3.3.1 only; version 3.3.2 only; version 3.11 only; version 3.12 only; …

Published 2003-10-20. Last modified 2026-06-16.