PHP < 5.3.1 - 'MultiPart/form-data' Denial of Service

ExploitDBExploitDB exploitExploitEDB-10242

PoC files

1 file

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ExploitDB
Analysisdeepseek-v4-pro:cloud ·

Technical assessment

Python script that sends crafted multipart/form-data POST requests with 16,000 file parts to exhaust temporary files on a PHP server, causing denial of service.

Backdoor review

No backdoor observed in reviewed code

The supplied Python script is a straightforward denial-of-service (DoS) exploit targeting PHP multipart/form-data temporary file exhaustion. It opens multiple TCP connections and sends crafted HTTP POST requests with 16,000 form-data parts. No backdoor, trojan, or deceptive behavior is present. The code performs only the advertised DoS attack and contains no concealed executable payloads, persistence mechanisms, credential theft, or unrelated remote access.

ClassificationExploit
Model confidence95%
AuthenticationNot required
Languagespython
Target softwarephp
Attack typesdenial of service
Evidence & reasoningClassification basis · observed behavior · safety review
Technical evidence

Classification basis and observed behavior

Classification basis

The script actively sends malicious HTTP requests designed to exhaust server resources, which is the definition of an exploit. It does not merely check for vulnerability presence.

exploits/php/dos/10242.py:12-14exploits/php/dos/10242.py:110-116

Requirements

  • Target must run a vulnerable PHP version (before 5.2.12 or 5.3.x before 5.3.1) that does not restrict temporary file creation for multipart/form-data requests.exploits/php/dos/10242.py:19-20
  • Attacker must be able to establish TCP connections to the target web server port.exploits/php/dos/10242.py:63-64

Observed behavior

  • Accepts target host, port, path, and optional thread count from command line.exploits/php/dos/10242.py:140-147
  • Spawns multiple threads, each sending 10 HTTP POST requests with a multipart/form-data body containing 16,000 file parts.exploits/php/dos/10242.py:100-104exploits/php/dos/10242.py:110-116exploits/php/dos/10242.py:149-152
  • Each request causes the PHP server to create a temporary file for each file part, exhausting disk space or inode resources.exploits/php/dos/10242.py:12-14
Safety-review evidence

Behaviors behind the backdoor verdict

Observables

DoS Mechanism
Sends HTTP POST with 16,000 multipart/form-data parts to exhaust PHP temporary filesThis is the advertised exploit behavior for CVE-2009-4017.exploits/php/dos/10242.py:100-104
Network Connection
Opens TCP connections to user-supplied host and portRequired for sending the DoS payload; no unexpected outbound connections.exploits/php/dos/10242.py:62-64
Threading
Uses threading.Thread to spawn multiple concurrent attack threadsStandard concurrency for DoS amplification; no hidden functionality.exploits/php/dos/10242.py:75-80
Review boundaries

What the analysis did not establish

  • Only the Python script source is analyzed; no external libraries, network captures, or execution logs are provided.
  • The script contains a logic error: sys.exit(0) inside the for loop in run() will terminate the thread after the first request, limiting the intended 10 requests per thread to 1.
  • Only the single Python file was reviewed; no external dependencies or referenced resources were inspected.
  • Binary files were flagged as metadata-only and not analyzed, but none were present in this artifact.
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