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CVE-2012-3546

org/apache/catalina/realm/RealmBase.java in Apache Tomcat 6.x before 6.0.36 and 7.x before 7.0.30, when FORM authentication is used, allows remote attackers to bypass security-constraint…

Published
Dec 19, 2012
Updated
Jun 16, 2026
Affected
0 pkgs
Patched
None yet
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
12.0%probability of exploitation in next 30 days
Moderate Risk96th percentile+9.76%
0.00%4.97%9.94%14.9%11.2%12.0%Dec 25Apr 26Jun 26

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.

Description

org/apache/catalina/realm/RealmBase.java in Apache Tomcat 6.x before 6.0.36 and 7.x before 7.0.30, when FORM authentication is used, allows remote attackers to bypass security-constraint checks by leveraging a previous setUserPrincipal call and then placing /j_security_check at the end of a URI.

Affected Products

1 product · 66 configurations
Application
tomcatapache
58 versions
6.06.0.06.0.16.0.26.0.36.0.46.0.56.0.66.0.76.0.86.0.96.0.10

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every apache tomcat deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

  2. Remediation status

    No patch has shipped for CVE-2012-3546 yet — track the apache tomcat advisory for a fixed release and apply the workarounds below in the meantime.

  3. Mitigate without a patch

    Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

  4. How O3 protects you

    O3 detects and blocks CVE-2012-3546 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2012-3546. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

org/apache/catalina/realm/RealmBase.java in Apache Tomcat 6.x before 6.0.36 and 7.x before 7.0.30, when FORM authentication is used, allows remote attackers to bypass security-constraint checks by leveraging a previous setUserPrincipal call and then placing /j_security_check at the end of a URI.
O3 Security · Runtime Protection

Is CVE-2012-3546 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2012-3546 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.