Submit #739384: Beetel Beetel 777VR1 Broadband Router Firmware Version: V01.00.09 / V01.00.09_55 CWE-521 — Weak Password Requirements

Title
Use of Hard-Coded Default Credentials on UART Diagnostic Interface

Affected Product
Product: Beetel 777VR1 Broadband Router
Firmware Version: V01.00.09 / V01.00.09_55
Distribution: ISP-provisioned firmware

Vulnerability Type
Authentication Bypass via Default Credentials

CWE
CWE-521 — Weak Password Requirements

Severity
High

Attack Vector
Physical (UART)

Description
The Beetel 777VR1 router exposes a UART-based diagnostic interface protected by authentication. The interface accepts well-known, vendor-supplied default credentials (admin / password) and does not enforce a mandatory password change on first use.
The default credentials remain valid in production firmware and provide access to a privileged diagnostic environment, including shell access and system-level commands.
An attacker with physical access to the UART interface can authenticate using publicly known credentials, resulting in unauthorized administrative access.

Proof : Please see proof with screenshots in detail at :
https://gist.github.com/raghav20232023/9c51cbd91f3798b1c10f3f30fb631633

Impact
Unauthorized administrative access, configuration manipulation, information disclosure, and potential full system compromise.

Preconditions
Physical access to the UART interface
Device running affected firmware

Mitigation
Remove default credentials from production firmware
Enforce mandatory password change on first login
Require strong, user-defined credentials

Credit
Discovered and reported by: RAGHAV AGRAWAL

• Source: ⚠️ https://gist.github.com/raghav20232023/9c51cbd91f3798b1c10f3f30fb631633
• User: raghav_2026 (UID 94388)
• Submission: 01/14/2026 22:52 (3 months ago)
• Moderation: 01/25/2026 10:43 (10 days later)
• Status: Accepted
• VulDB entry: 342797 [Beetel 777VR1 up to 01.00.09/01.00.09_55 UART Interface weak password]
• Points: 20