ZDI-22-1614: TP-Link TL-WR940N httpd Use of Insufficiently Random Values Authentication Bypass Vulnerability

This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of TP-Link TL-WR940N routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the httpd service, which listens on TCP port 80 by default. The issue results from the lack of sufficient randomness in the sequnce numbers used for session managment. An attacker can leverage this vulnerability to bypass authentication on the system.

Affected Software

1 affected component
TP-Link TL-WR940N

Event History

Mar 24, 2025
Advisory Published
via ZDI·03:10 PM

Frequently Asked Questions

1

What is the severity of ZDI-22-1614?

The vulnerability ZDI-22-1614 is classified as a critical security issue that allows unauthorized access.

2

How do I fix ZDI-22-1614?

To fix ZDI-22-1614, update your TP-Link TL-WR940N router to the latest firmware version provided by TP-Link.

3

Who is affected by ZDI-22-1614?

ZDI-22-1614 affects users of TP-Link TL-WR940N routers that have not mitigated the vulnerability.

4

What type of vulnerability is ZDI-22-1614?

ZDI-22-1614 is an authentication bypass vulnerability in the httpd service of TP-Link TL-WR940N routers.

5

Can ZDI-22-1614 be exploited remotely?

Yes, ZDI-22-1614 can be exploited by network-adjacent attackers without requiring authentication.

Contact

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