Executive brief
Sendmail is a widely used mail transfer agent responsible for routing and delivering email across the internet. A critical vulnerability in how the software handles email attachments (MIME conversion) allows an attacker to take complete control of the mail server. This could lead to the theft of sensitive communications, total service disruption, or the server being used as a staging point for further attacks on the internal network.
Technical details
A stack-based buffer overflow exists in Sendmail versions 8.8.3 and 8.8.4 within the MIME conversion routines. The vulnerability is triggered when the application processes specially crafted MIME messages, leading to memory corruption. An unauthenticated remote attacker can exploit this by sending a malicious email to the affected server. Successful exploitation allows for arbitrary code execution with the privileges of the Sendmail process, typically root, resulting in full system compromise. Users should upgrade to a patched version of Sendmail (8.8.5 or later) to mitigate this risk.
Affected products
- Sendmail Sendmail 8.8.3, 8.8.4
Timeline
- 1997-01-28: disclosed: Initial publication date