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CVE-2013-2135

CVE-2013-2135 is a Code Injection vulnerability in apache struts. O3 Security detects and blocks CVE-2013-2135 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.

Apache Struts 2 before 2.3.14.3 allows remote attackers to execute arbitrary OGNL code via a request with a crafted value that contains both "${}" and "%{}" sequences, which causes…

Published
Jul 16, 2013
Updated
Jun 16, 2026
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Jun 16, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Description

Apache Struts 2 before 2.3.14.3 allows remote attackers to execute arbitrary OGNL code via a request with a crafted value that contains both "${}" and "%{}" sequences, which causes the OGNL code to be evaluated twice.

Affected Products

1 product · 1 configurations
Application
strutsapache
≥ 2.0.0 && < 2.3.14.3
range

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every apache struts 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. Fix

    Apply the apache struts security patch or hotfix for CVE-2013-2135 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    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-2013-2135 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-2013-2135. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Apache Struts 2 before 2.3.14.3 allows remote attackers to execute arbitrary OGNL code via a request with a crafted value that contains both "${}" and "%{}" sequences, which causes the OGNL code to be evaluated twice.
O3 Security · Runtime Protection

Is CVE-2013-2135 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2013-2135 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

CVE-2013-2135: STRUTS Code Injection | O3 Security