CVE-2026-16771

HIGH

At&t Arris BGW210‑700 < 2.7.7 - Missing Authentication for Critical Function

Title source: rule
STIX 2.1

Description

In firmware versions 2.7.7 and earlier, the Arris BGW210‑700 gateway fails to enforce any server‑side authentication on its /cgi-bin/*.ha management endpoints, relying solely on client‑side CSS/JavaScript gating that can be bypassed by any HTTP client. This allows unauthenticated attackers on the LAN to read sensitive configuration data, modify persistent device settings, or trigger backend diagnostic operations. The issue appears systemic across the CGI handler chain.

References (2)

Core 2
Core References
Third Party Advisory, US Government Resource
https://www.kb.cert.org/vuls/id/141367

Scores

CVSS v3 8.8
EPSS 0.0025
EPSS Percentile 16.5%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-306
Status published
Products (1)
AT&T/Arris BGW210‑700 < 2.7.7
Published Jul 28, 2026
Tracked Since Jul 29, 2026