Apache Struts - RCE (CVE-2017-9805)

CVE-2017-9805 is a critical vulnerability in the REST Plugin of Apache Struts versions 2.1.1 through 2.3.x before 2.3.34 and 2.5.x before 2.5.13, where unsafe deserialization of XML payloads via XStreamHandler can lead to remote code execution. Attackers can exploit this flaw to execute arbitrary code on the affected server, potentially leading to full system compromise and further attacks within the network.

CrowdSec has been tracking this vulnerability and its exploits since 30th of June 2025.

CrowdSec network observations suggest that most exploitation of CVE-2017-9805 involves focused reconnaissance to identify viable targets. Attackers typically tailor their campaigns based on system exposure and configuration. It is unlikely that a given attack is accidental. CrowdSec network telemetry also shows that exploitation of CVE-2017-9805 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Attackers exploit this vulnerability by sending crafted POST requests with malicious XML payloads to /struts2-rest-showcase/orders/ endpoints, leading to remote code execution via unsafe deserialization.