CVE-2012-5533
CWE-399Published: November 24, 2012· Updated: Jun 16, 2026
Official Description
The http_request_split_value function in request.c in lighttpd before 1.4.32 allows remote attackers to cause a denial of service (infinite loop) via a request with a header containing an empty token, as demonstrated using the "Connection: TE,,Keep-Alive" header.
Technical Analysis
CVE-2012-5533 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-2012-5533. 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 (32)
Quick Facts
Related CVEs (CWE-399)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2012-5533 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts