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CVE-2009-0781

CVE-2009-0781 is a Cross-site Scripting (XSS) vulnerability in apache tomcat. O3 Security detects and blocks CVE-2009-0781 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.

Cross-site scripting (XSS) vulnerability in jsp/cal/cal2.jsp in the calendar application in the examples web application in Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27,…

Published
Mar 9, 2009
Updated
Jun 16, 2026
Affected
0 pkgs
Patched
None yet
Exploits
None indexed

Description

Cross-site scripting (XSS) vulnerability in jsp/cal/cal2.jsp in the calendar application in the examples web application in Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18 allows remote attackers to inject arbitrary web script or HTML via the time parameter, related to "invalid HTML."

Affected Products

1 product · 85 configurations
Application
tomcatapache
83 versions
4.1.04.1.14.1.24.1.34.1.44.1.54.1.64.1.74.1.84.1.94.1.104.1.11

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-2009-0781 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-2009-0781 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-2009-0781. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Cross-site scripting (XSS) vulnerability in jsp/cal/cal2.jsp in the calendar application in the examples web application in Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18 allows remote attackers to inject arbitrary web script or HTML via the time parameter, related to "invalid HTML."
O3 Security · Runtime Protection

Is CVE-2009-0781 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2009-0781 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.