CVE-2009-3555 is a critical-severity (CVSS 9.8) CWE-295 vulnerability in org.apache.tomcat:tomcat. 7 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for org.apache.tomcat:tomcat — see the affected versions and patch details below.
Apache Tomcat affected by vulnerability in TLS and SSL protocol
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2009-3555.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcatReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft Internet Information Services (IIS) 7.0, mod_ssl in the Apache HTTP Server 2.2.14 and earlier, OpenSSL before 0.9.8l, GnuTLS 2.8.5 and earlier, Mozilla Network Security Services (NSS) 3.12.4 and earlier, multiple Cisco products, and other products, does not properly associate renegotiation handshakes with an existing connection, which allows man-in-the-middle attackers to insert data into HTTPS sessions, and possibly other types of sessions protected by TLS or SSL, by sending an unauthenticated request that is processed retroactively by a server in a post-renegotiation context, related to a "plaintext injection" attack, aka the "Project Mogul" issue.
Apache Tomcat was affected by this issue and introduced a workaround in versions 7.0.10, 6.0.32, and 5.5.33.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat | ≥ 7.0.0&&< 7.0.10 | 7.0.10org.apache.tomcat:tomcat:7.0.10 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 6.0.0&&< 6.0.32 | 6.0.32org.apache.tomcat:tomcat:6.0.32 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 5.0.0&&< 5.5.33 | 5.5.33org.apache.tomcat:tomcat:5.5.33 |
Affected Products
http serverapacheubuntu linuxcanonicaldebian linuxdebiannginxf5fedorafedoraprojectgnutlsgnuResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Mozilla NSS - NULL Character CA SSL Certificate Validation Security Bypass
by Dan Kaminsky · Nov 10, 2009
TLS - Renegotiation
by RedTeam Pentesting · Dec 21, 2009
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat to 7.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2009-3555 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Additional information can be found in the Red Hat Knowledgebase article: https://access.redhat.com/articles/20490
| Product | Fixed in | Advisory |
|---|---|---|
| Extras for RHEL 3 | java-1.4.2-ibm-0:1.4.2.13.4-1jpp.1.el3 | RHSA-2010:0155 |
| Extras for RHEL 3 | java-1.4.2-ibm-0:1.4.2.13.6-1jpp.3.el3 | RHSA-2010:0786 |
| Extras for RHEL 4 | java-1.6.0-ibm-1:1.6.0.7-1jpp.3.el4 | RHSA-2009:1694 |
| Extras for RHEL 4 | java-1.5.0-ibm-1:1.5.0.11.1-1jpp.3.el4 | RHSA-2010:0130 |
| Extras for RHEL 4 | java-1.6.0-sun-1:1.6.0.19-1jpp.1.el4 | RHSA-2010:0337 |
| Extras for RHEL 4 | java-1.5.0-sun-0:1.5.0.22-1jpp.3.el4 | RHSA-2010:0338 |
| Extras for RHEL 4 | java-1.6.0-sun-1:1.6.0.22-1jpp.1.el4 | RHSA-2010:0770 |
| Extras for RHEL 4 | java-1.5.0-ibm-1:1.5.0.12.2-1jpp.1.el4 | RHSA-2010:0807 |
Frequently Asked Questions
Is CVE-2009-3555 in your dependencies?
Find it across Maven, including transitive dependencies.