// For flags

CVE-2022-43636

TP-Link TL-WR940N httpd Use of Insufficiently Random Values Authentication Bypass Vulnerability

Severity Score

8.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of TP-Link TL-WR940N 6_211111 3.20.1(US) 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. Was ZDI-CAN-18334.

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.

*Credits: ExLuck
CVSS Scores
Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Adjacent
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2022-10-21 CVE Reserved
  • 2022-11-21 CVE Published
  • 2024-08-03 CVE Updated
  • 2024-10-19 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-330: Use of Insufficiently Random Values
CAPEC
References (1)
URL Tag Source
https://www.zerodayinitiative.com/advisories/ZDI-22-1614 Third Party Advisory
URL Date SRC
URL Date SRC
URL Date SRC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Tp-link
Search vendor "Tp-link"
 Tl-wr940n Firmware
Search vendor "Tp-link" for product "Tl-wr940n Firmware"
 6_211111_3.20.1
Search vendor "Tp-link" for product "Tl-wr940n Firmware" and version "6_211111_3.20.1"
-
Affected
in Tp-link
Search vendor "Tp-link"
 Tl-wr940n
Search vendor "Tp-link" for product "Tl-wr940n"
--
Safe