CVE-2011-5009
NVD-CWE-OtherPublished: December 25, 2011· Updated: Jun 16, 2026
Official 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.
Technical Analysis
CVE-2011-5009 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A proof-of-concept (PoC) exploit exists for CVE-2011-5009. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (14)
Quick Facts
Related CVEs (NVD-CWE-Other)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2011-5009 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts