Description
The Catalina org.apache.catalina.connector.http package in Tomcat 4.0.x up to 4.0.3 allows remote attackers to cause a denial of service via several requests that do not follow the HTTP protocol, which causes Tomcat to reject later requests.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 3.0 | tomcat4 | 4.0.3-3woody3 | DSA-395 |
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.
Exploit-DB 1
- Apache Tomcat 4.0.x - Non-HTTP Request Denial of Service EDB-23245 · dos · Oct 15, 2003 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.apache.tomcat:tomcat | >= 4.0, < 4.1.0 | 4.1.0 | GHSA-7wj2-48c4-2684 |
Advisories 1
- DSA-395 tomcat4 - incorrect input handling Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://tomcat.apache.org/security-4.html
- 30908 third-party-advisory
- 8824 vdb-entry
- 239312 vendor-advisory
- 30899 third-party-advisory
- ADV-2008-1979 vdb-entry
- DSA-395 vendor-advisory
- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=215506
- tomcat-non-http-dos(13429) vdb-entry
- [tomcat-dev] 20190319 svn commit: r1855831 [21/30] - in /tomcat/site/trunk: ./ docs/ xdocs/ mailing-list
- [tomcat-dev] 20190325 svn commit: r1856174 [19/29] - in /tomcat/site/trunk: docs/ xdocs/ xdocs/stylesheets/ mailing-list
- [tomcat-dev] 20200213 svn commit: r1873980 [24/34] - /tomcat/site/trunk/docs/ mailing-list