Hydra - Stack Buffer Overflow

ExploitDBExploitDB exploitExploitEDB-52622

PoC files

1 file

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ExploitDB
Analysisdeepseek-v4-pro:cloud ·

Technical assessment

Python script that implements a malicious SMTP server to trigger a stack buffer overflow in Hydra's NTLM authentication handler by sending a crafted NTLM Type-2 challenge with an excessively long domain name.

Backdoor review

No backdoor observed in reviewed code

The PoC is a straightforward SMTP server that sends a crafted NTLM Type-2 challenge to trigger a known stack buffer overflow in vulnerable Hydra clients. No backdoor, deceptive payload, or concealed operator-directed harm is present.

ClassificationExploit
Model confidence95%
AuthenticationNot required
Languagespython
Target softwareHydra
Attack typesstack buffer overflow
Evidence & reasoningClassification basis · observed behavior · safety review
Technical evidence

Classification basis and observed behavior

Classification basis

The script actively sends a malicious payload (crafted NTLM Type-2 challenge) designed to overflow a stack buffer in a vulnerable client, which is the definition of an exploit. It does not merely check for the vulnerability; it exercises it to cause a crash (SIGSEGV).

exploits/linux/remote/52622.py:1exploits/linux/remote/52622.py:15exploits/linux/remote/52622.py:17-19exploits/linux/remote/52622.py:29exploits/linux/remote/52622.py:57-76exploits/linux/remote/52622.py:100-103

Requirements

  • A vulnerable Hydra client (<= 9.7) must connect to the malicious server and attempt NTLM authentication.exploits/linux/remote/52622.py:11exploits/linux/remote/52622.py:28exploits/linux/remote/52622.py:33-34

Observed behavior

  • Starts a TCP server on port 2525 that speaks SMTP and advertises NTLM authentication.exploits/linux/remote/52622.py:78-83exploits/linux/remote/52622.py:95
  • When a client sends an NTLM authentication token, the server responds with a crafted NTLM Type-2 challenge containing a 400-byte domain name.exploits/linux/remote/52622.py:57-76exploits/linux/remote/52622.py:100-103
  • The oversized domain name causes a stack buffer overflow in the Hydra client when it processes the base64-encoded challenge, leading to a SIGSEGV.exploits/linux/remote/52622.py:17-19exploits/linux/remote/52622.py:29
Safety-review evidence

Behaviors behind the backdoor verdict

Observables

Network Server
SMTP server on 0.0.0.0:2525The PoC acts as a malicious SMTP server to deliver the overflow payload.exploits/linux/remote/52622.py:78-83
Exploit Trigger
Crafted NTLM Type-2 challenge with 400-byte domain nameThe overflow is triggered by a long domain string in the NTLM challenge, matching the CVE description.exploits/linux/remote/52622.py:57-76
Review boundaries

What the analysis did not establish

  • The analysis is based solely on the provided Python script; no external dependencies, libraries, or the vulnerable Hydra binary were inspected or executed.
  • The script's effectiveness and reliability are not verified; it is treated as untrusted data.
  • Only the supplied text file was reviewed; no binary or external resources were inspected.
  • The PoC does not include a payload for remote code execution; it only triggers a crash (SIGSEGV) as stated in the comments.
Model interpretation

This review is limited to the supplied PoC code and context. It does not assert that the code works or is safe to execute.

Linked vulnerabilities

1