Vulnerability · Published Apr 24, 2023 · Assigned by Zyxel

CVE-2023-22915

High 7.5

In plain English

A high-severity buffer overflow in USG FLEX 50(W) firmware from Zyxel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)1.1%top 35.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

A buffer overflow vulnerability in the “fbwifi_forward.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.30 through 5.35, USG20(W)-VPN firmware versions 4.30 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote unauthenticated attacker to cause DoS conditions by sending a crafted HTTP request if the Facebook WiFi function were enabled on an affected device.

Affected products (as reported)

Vendor	Product	Versions
Zyxel	USG FLEX series firmware	4.50 through 5.35
Zyxel	USG FLEX 50(W) firmware	4.30 through 5.35
Zyxel	USG20(W)-VPN firmware	4.30 through 5.35
Zyxel	VPN series firmware	4.30 through 5.35

Weakness: CWE-120 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-of-firewalls-and-aps