CVE-2009-3555 is a critical-severity (CVSS 9.8) CWE-295 vulnerability in org.apache.tomcat:tomcat. 7 public exploit references exist, 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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2009-3555 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
TLS - Renegotiation
by RedTeam Pentesting · Dec 21, 2009
Mozilla NSS - NULL Character CA SSL Certificate Validation Security Bypass
by Dan Kaminsky · Nov 10, 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2009-3555 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2009-3555. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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?
O3 Security finds CVE-2009-3555 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.