CVE-2025-54656
MEDIUMCVE-2025-54656 is a medium-severity (CVSS 6.5) CWE-117 vulnerability in apache struts extras. O3 Security detects and blocks CVE-2025-54656 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.
** UNSUPPORTED WHEN ASSIGNED ** Improper Output Neutralization for Logs vulnerability in Apache Struts. This issue affects Apache Struts Extras: before 2. When using LookupDispatchAction,…
Description
** UNSUPPORTED WHEN ASSIGNED ** Improper Output Neutralization for Logs vulnerability in Apache Struts.
This issue affects Apache Struts Extras: before 2.
When using LookupDispatchAction, in some cases, Struts may print untrusted input to the logs without any filtering. Specially-crafted input may lead to log output where part of the message masquerades as a separate log line, confusing consumers of the logs (either human or automated).
As this project is retired, we do not plan to release a version that fixes this issue. Users are recommended to find an alternative or restrict access to the instance to trusted users.
NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
Affected Products
struts extrasapacheDetection & mitigation playbook
Vendor / applianceDetect
Inventory every apache struts extras 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.
Fix
Apply the apache struts extras security patch or hotfix for CVE-2025-54656 on the affected version, following the vendor advisory for your exact build.
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.
How O3 protects you
O3 detects and blocks CVE-2025-54656 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-2025-54656. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-54656 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2025-54656 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.