CVE-2023-22915

24.04.2023, 17:15

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.

Classic Buffer Overflow

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Zyxel	CNA	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVE	ADP	---				---
CISA-ADP	ADP	---				---

Base Score

CVSS 3.x

EPSS Score

Percentile: 74%

Vendor	Product	Version
zyxel	usg_flex_100_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	usg_flex_100w_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	usg_flex_200_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	usg_flex_50_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	usg_flex_50w_firmware	4.30 ≤ 𝑥 ≤ 5.35
zyxel	usg_flex_500_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	usg_flex_700_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	vpn100_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	vpn1000_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	vpn300_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	vpn50_firmware	4.50 ≤ 𝑥 ≤ 5.35
zyxel	usg_20w-vpn_firmware	4.30 ≤ 𝑥 ≤ 5.35

𝑥

= Vulnerable software versions

Common Weakness Enumeration

CWE-120 - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
The program copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.

References

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