CVE-2024-6343

Severity: medium (CVSS 4.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-09-03 · updated 2026-06-17
Weakness: CWE-120

Description

A buffer overflow vulnerability in the CGI program of Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W) series firmware versions from V4.16 through V5.38, and USG20(W)-VPN series firmware versions from V4.16 through V5.38 could allow an authenticated attacker with administrator privileges to cause denial of service (DoS) conditions by sending a crafted HTTP request to a vulnerable device.

Affected products

Zyxel firewall (ZLD): from 4.32 before 5.39; from 4.50 before 5.39; from 4.16 before 5.39 — fixed in 5.39

How to fix

Upgrade to a fixed version: Zyxel firewall (ZLD) 5.39. Check the vendor advisory for mitigations.

References

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-09-03-2024

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