A stack buffer overflow in the thc-hydra authentication tool allows a malicious server to trigger remote code execution when processing crafted NTLM challenges.

The application suffers from a stack buffer overflow when parsing NTLM Type-2 challenges across multiple protocols, including SMTP, HTTP, and IMAP. An attacker controlling a malicious server can send an excessively long domain string, triggering a buffer overflow that can lead to remote code execution.

The CVSS score of 8.8 reflects the high severity of potential remote code execution. Because thc-hydra is often used in security testing environments, a compromise could lead to the exposure of sensitive credentials, internal network mapping, and the potential pivot point for further lateral movement within an organization's security infrastructure.

Immediate Action: Update thc-hydra to the version containing the fix implemented in commit 9cc84c2.

Proactive Monitoring: Monitor for unusual application crashes or memory access violations when performing authentication-based security testing against untrusted or potentially malicious targets.

Compensating Controls: Ensure that systems running thc-hydra are compiled with modern stack protection mechanisms (e.g., stack canaries, ASLR) to mitigate the impact of buffer overflow attempts.

Public Exploit Available: false

Although this tool is primarily used by security professionals, it is a frequent target for attackers looking to compromise testing infrastructure. All users should update to the patched version immediately to ensure that testing activities do not inadvertently result in the compromise of their own workstations or servers.