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Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

CVE-2020-11462

High
7.5/10

Summary

An issue was discovered in OpenVPN Access Server before 2.7.0 and 2.8.x before 2.8.3. With the full featured RPC2 interface enabled, it is possible to achieve a temporary DoS state of the management interface when sending an XML Entity Expansion (XEE) payload to the XMLRPC based RPC2 interface. The duration of the DoS state depends on available memory and CPU speed. The default restricted mode of the RPC2 interface is NOT vulnerable.

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

CWE-776 - Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

The software uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.

References

Advisory Timeline

  • Published