CVE-2018-11776
Published: November 3, 2021
Official Description
Apache Struts contains a vulnerability that allows for remote code execution under two circumstances. One, where the alwaysSelectFullNamespace option is true and the value isn't set for a result defined in underlying configurations and in same time, its upper package configuration have no or wildcard namespace. Or, using URL tag which doesn't have value and action set and in same time, its upper package configuration have no or wildcard namespace.
CISA KEV Advisory
Apache Struts Remote Code Execution Vulnerability
Apache Struts contains a vulnerability that allows for remote code execution under two circumstances. One, where the alwaysSelectFullNamespace option is true and the value isn't set for a result defined in underlying configurations and in same time, its upper package configuration have no or wildcard namespace. Or, using URL tag which doesn't have value and action set and in same time, its upper package configuration have no or wildcard namespace.
Apply updates per vendor instructions.
Risk Analysis
This Apache Struts vulnerability enables remote code execution under specific configuration scenarios, making it a critical threat. Its high EPSS score and inclusion in CISA's KEV catalog highlight its urgency and confirmed exploitation. Successful exploitation could lead to full system compromise.
This vulnerability is actively exploited in the wild and is part of CISA's KEV catalog, indicating a severe and immediate threat. The conditions for exploitation involve specific Struts configurations, but the impact is remote code execution.
Organizations using Apache Struts should immediately review their configurations and upgrade to a patched version to prevent remote code execution. Ensure that the 'alwaysSelectFullNamespace' option is handled correctly and URL tags are properly configured.
Technical Analysis
CVE-2018-11776 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2018-11776 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2018-11776 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1