Arista NG Firewall replace_marker Exposed Dangerous Function Authentication Bypass Vulnerability

November 25th, 2025
ZDI-25-1019 ZDI-CAN-27007

CVE ID

CVE-2025-6979

CVSS Score

8.8 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected Vendors

Arista

Affected Products

NG Firewall

Vulnerability Details

This vulnerability allows remote attackers to to bypass authentication on affected installations of Arista NG Firewall. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the handler.py module. The issue results from an exposed dangerous method. An attacker can leverage this vulnerability to bypass authentication on the system.

Additional Details

Arista has issued an update to correct this vulnerability. More details can be found at:
https://www.arista.com/en/support/advisories-notices/security-advisory/22535-security-advisory-0123

Disclosure Timeline

  • 2025-06-18 - Vulnerability reported to vendor
  • 2025-11-25 - Coordinated public release of advisory
  • 2025-11-25 - Advisory Updated

Credit

Gereon Huppertz

Back to Advisories