Critical CVSS 9.8

Overview

Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exim. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the handling of NTLM challenge requests. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of the service account.
. Was ZDI-CAN-17515.

Risk analysis

This vulnerability is rated 🔴 CRITICAL.

  • CVSS: 9.8 (CRITICAL)
  • Detected tags: buffer, rce (tag impact: VERY HIGH)

Recommended actions:

  • Patch/upgrade immediately (remote code execution).
  • Reduce exposure (WAF/segmentation), minimize attack surface.

Recommended tools

Tags