Episerver 7 - XXE (CVE-2017-17762)

CVE-2017-17762 is an XML external entity (XXE) vulnerability in Episerver 7 patch 4 and earlier, which allows remote attackers to read arbitrary files on the server by submitting maliciously crafted XML requests to util/xmlrpc/Handler.ashx. This flaw could be exploited to access sensitive information, potentially leading to further attacks or data breaches.

CrowdSec has been tracking this vulnerability and its exploits since 7th of January 2026.

Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2017-17762 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning. Telemetry from the CrowdSec network also shows that exploitation activity for CVE-2017-17762 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2017-17762 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.

Attackers exploit this vulnerability by sending crafted XML payloads to the /util/xmlrpc/Handler.ashx endpoint, attempting to trigger XML External Entity (XXE) processing for unauthorized file access or external resource loading.