Skip to main content

Improper Restriction of XML External Entity Reference

CVE-2017-5661

Severity High
Score 7.3/10

Summary

In Apache FOP before 2.2, files lying on the filesystem of the server which uses FOP can be revealed to arbitrary users who send maliciously formed SVG files. The file types that can be shown depend on the user context in which the exploitable application is running. If the user is root a full compromise of the server - including confidential or sensitive files - would be possible. XXE can also be used to attack the availability of the server via denial of service as the references within a xml document can trivially trigger an amplification attack.

  • LOW
  • NETWORK
  • NONE
  • UNCHANGED
  • REQUIRED
  • LOW
  • HIGH
  • HIGH

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