Skip to main content

Improper Restriction of XML External Entity Reference

CVE-2020-25817

Severity Medium
Score 4.8/10

Summary

SilverStripe before 4.7.4, 4.8.x before 4.8.0 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).

  • LOW
  • NETWORK
  • LOW
  • CHANGED
  • REQUIRED
  • HIGH
  • LOW
  • NONE

CWE-611 - Improper Restriction of XML External Entity Reference

Listed 4th in the 'OWASP Top Ten', XML External Entities (XXE) vulnerability allows attackers to provide an XML input that contains an external entity. When the XML is parsed, it can cause data extraction and manipulation, execution of commands, denial-of-service attacks, and server-side request forgery.

Advisory Timeline

  • Published