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.

According to CrowdSec data, while opportunistic exploitation dominates, a portion of threat actors trying to exploit CVE-2017-9805 apply basic targeting methods such as port or service detection. This indicates emerging patterns of selective targeting. Data from the CrowdSec community also indicates a gradual decrease in attacks targeting CVE-2017-9805. While still present in the wild, exploitation levels have dropped noticeably week-over-week. This may signal that the vulnerability is becoming less relevant or that defenses are improving fast enough for attackers to lose interest.

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.