CVE & CISA-KEV Catalog

CVE-2009-0033

MEDIUMEPSS 95th pctl
5.0
CVSS v2
NVD

Description

Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18, when the Java AJP connector and mod_jk load balancing are used, allows remote attackers to cause a denial of service (application outage) via a crafted request with invalid headers, related to temporary blocking of connectors that have encountered errors, as demonstrated by an error involving a malformed HTTP Host header.

CWE-20Improper Input Validation

CVSS v2 Vector

No CVSS vector data available.

Exploit Intelligence

10.05%probability of exploitation in 30 days
95thpercentile

Very high risk: more likely to be exploited than 95% of all known CVEs.

References

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.