# CVE-2017-17762: Episerver 7 - XXE

> Live exploitation tracking for CVE-2017-17762 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2017-17762

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 7.5
- **Public exploit available:** Yes
- **Affected products:** Optimizely Episerver 7
- **Weaknesses:** CWE-611 (Improper Restriction of XML External Entity Reference)
- **Tags:** web_application

## Description

XML external entity (XXE) vulnerability in Episerver 7 patch 4 and earlier allows remote attackers to read arbitrary files via a crafted DTD in an XML request involving util/xmlrpc/Handler.ashx.

## CrowdSec analysis

[CVE-2017-17762](https://euvd.enisa.europa.eu/vulnerability/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.

## Timeline

- 2018-08-29: CVE Published. CVE-2017-17762 is published to NVD.
- 2026-01-07: Rule Released. CrowdSec releases a rule to detect CVE-2017-17762 exploitation attempts against the CrowdSec Network.
- 2026-01-14: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2017-17762 for the first time.

## References

- https://kryptera.se/sarbarhet-i-episerver/
- https://gist.github.com/jonaslejon/5f92779848360a1a1e676af0795bd9aa
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2017/CVE-2017-17762.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2017-17762) follows observed exploitation activity for CVE-2017-17762. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.