Description
The CmpWebServer.dll module in the Control service in 3S CoDeSys 3.4 SP4 Patch 2 allows remote attackers to cause a denial of service (NULL pointer dereference) via (1) a crafted Content-Length in an HTTP POST or (2) an invalid HTTP request method.
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 2
- CoDeSys 3.4 - POST Null Pointer Content-Length Parsing Remote Denial of Service EDB-36377 · dos · Nov 30, 2011 · verified
- CoDeSys 3.4 - Null Pointer Invalid HTTP Request Parsing Remote Denial of Service EDB-36378 · dos · Nov 30, 2011 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- ICSA-12-006-01 3S CoDeSys Vulnerabilities CISA ICS & IT advisories · Jun 9, 2025
References
- http://www.us-cert.gov/control_systems/pdf/ICS-ALERT-11-336-01A.pdf
- 20111129 Vulnerabilities in 3S CoDeSys 3.4 SP4 Patch 2 mailing-list
- 47018 third-party-advisory
- http://aluigi.altervista.org/adv/codesys_1-adv.txt
- 77388 vdb-entry
- codesys-cmpwebserver-dos(71533) vdb-entry
- 77389 vdb-entry