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

CVE-2021-3541

Medium
6.5/10

Summary

A flaw was found in libxml2 before 2.9.11. Exponential entity expansion attack its possible bypassing all existing protection mechanisms and leading to denial of service.

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