CVE-2021-42659

Name: CVE-2021-42659
Creator: NVD / NIST
Published: 2022-05-24T12:15:07.59+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.81%

Last modified Jun 17, 2026

CVE-2021-42659 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. There is a buffer overflow vulnerability in the Web server httpd of the router in Tenda router devices such as Tenda AC9 V1.0 V15.03.02.19(6318) and Tenda AC9 V3.0 V15.03.06.42_multi. When setting the virtual service, the httpd program will crash and exit when the super-long list parameter occurs.. EPSS estimates a 0.81% chance of exploitation in the next 30 days.

Description

There is a buffer overflow vulnerability in the Web server httpd of the router in Tenda router devices such as Tenda AC9 V1.0 V15.03.02.19(6318) and Tenda AC9 V3.0 V15.03.06.42_multi. When setting the virtual service, the httpd program will crash and exit when the super-long list parameter occurs.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.81%

52.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-119

Affected Software

Vendor	Product	Versions
Tenda	Ac9 Firmware	15.03.05.19\(6318\)
Tenda	Ac9 Firmware	15.03.06.42_multi

References

https://github.com/Lyc-heng/routers/blob/main/routers/stack4.mdExploit, Third Party Advisory
https://www.cnvd.org.cn/flaw/show/CNVD-2021-24948Third Party Advisory
https://github.com/Lyc-heng/routers/blob/main/routers/stack4.mdExploit, Third Party Advisory
https://www.cnvd.org.cn/flaw/show/CNVD-2021-24948Third Party Advisory

Timeline

Published: May 24, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-42659?

How severe is CVE-2021-42659?

CVE-2021-42659 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.81% probability of exploitation in the next 30 days.

How do I fix CVE-2021-42659?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-42659?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST