How severe is CVE-2022-43636?

CVE-2022-43636 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2022-43636 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-43636?

CVE-2022-43636 affects Tp-link Tl-wr940n Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2022-43636?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2022-43636 published?

CVE-2022-43636 was published on 2023-03-29 and last updated on 2026-06-17.

CVE-2022-43636

CVE-2022-43636 is a high-severity vulnerability in Tp-link Tl-wr940n Firmware with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-330.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-330
Affected product: Tp-link Tl-wr940n Firmware
Published: 2023-03-29
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2022-43636?: 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.
How severe is CVE-2022-43636?: CVE-2022-43636 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2022-43636 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-43636?: CVE-2022-43636 affects Tp-link Tl-wr940n Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2022-43636?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2022-43636 published?: CVE-2022-43636 was published on 2023-03-29 and last updated on 2026-06-17.

References

https://www.zerodayinitiative.com/advisories/ZDI-22-1614/

Affected products (1)

cpe:2.3:o:tp-link:tl-wr940n_firmware:6_211111_3.20.1:*:*:*:*:*:*:*

More vulnerabilities in Tp-link Tl-wr940n Firmware

CVE-2023-36355 — Critical (CVSS 9.9): TP-Link TL-WR940N V4 was discovered to contain a buffer overflow via the ipStart parameter at…
CVE-2023-33538 — High (CVSS 8.8): TP-Link TL-WR940N V2/V4, TL-WR841N V8/V10, and TL-WR740N V1/V2 was discovered to contain a command injection…
CVE-2022-24355 — High (CVSS 8.8): This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of TP-Link…
CVE-2019-6989 — High (CVSS 8.8): TP-Link TL-WR940N is vulnerable to a stack-based buffer overflow, caused by improper bounds checking by the…
CVE-2025-6151 — High (CVSS 8.2): A vulnerability has been found in TP-Link TL-WR940N V4 and TL-WR841N V11. Affected by this issue is some unknown…
CVE-2023-33537 — High (CVSS 8.1): TP-Link TL-WR940N V2/V4, TL-WR841N V8/V10, and TL-WR740N V1/V2 was discovered to contain a buffer overflow via the…

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