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Incomplete Denylist to Cross-Site Scripting

CVE-2025-20240

Severity Medium
Score 6.1/10

Summary

A vulnerability in the Web Authentication feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a reflected cross-site scripting attack (XSS) on an affected device. This vulnerability is due to improper sanitization of user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a malicious link. A successful exploit could allow the attacker to execute a reflected XSS attack and steal user cookies from the affected device.

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

CWE-692 - Incomplete Denylist to Cross-Site Scripting

The product uses a denylist-based protection mechanism to defend against XSS attacks, but the denylist is incomplete, allowing XSS variants to succeed.

References

Advisory Timeline

  • Published