CVE-2022-43636

Authentication bypass via predictable session sequence numbers

Published Mar 29, 2023 · Updated Feb 12, 2025

Authentication bypass in TP-Link TL-WR940N 6_211111 3.20.1(US) allows network-adjacent attackers to access the router via HTTP. The httpd service on TCP port 80 uses insufficiently random sequence numbers for session management, making valid session identifiers predictable. No authentication or user interaction is required, and successful exploitation grants control available through the management interface.

CVSS severity7.5
High
EPSS probability0.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in TP-Link TL-WR940N 6_211111 3.20.1(US) allows network-adjacent attackers to access the router via HTTP. The httpd service on TCP port 80 uses insufficiently random sequence numbers for session management, making valid session identifiers predictable. No authentication or user interaction is required, and successful exploitation grants control available through the management interface.

The record

CVE
CVE-2022-43636
Published
Mar 29, 2023
Updated
Feb 12, 2025
Vendor
TP-Link Systems Inc.
Product
TL-WR940N
Classifications
CWE-330, T1190
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 29, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=6_211111 3.20.1(US)

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

TP-Link Systems Inc. · TL-WR940Nversion=6_211111 3.20.1(US)

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5Zero Day InitiativeCVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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