CVE-2023-34140

17.07.2023, 18:15

A buffer overflow vulnerability in the Zyxel ATP series firmware versions 4.32 through 5.36 Patch 2, USG FLEX series firmware versions 4.50 through 5.36 Patch 2,  USG FLEX 50(W) series firmware versions 4.16 through 5.36 Patch 2, USG20(W)-VPN series firmware versions 4.16 through 5.36 Patch 2, VPN series firmware versions 4.30 through 5.36 Patch 2,NXC2500 firmware versions 6.10(AAIG.0) through 6.10(AAIG.3), and NXC5500 firmware versions 6.10(AAOS.0) through 6.10(AAOS.4), could allow an unauthenticated, LAN-based attacker to cause denial of service (DoS) conditions by sending a crafted request to the CAPWAP daemon.

Classic Buffer Overflow

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	6.5 MEDIUM	ADJACENT_NETWORK	LOW	NONE	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Zyxel	CNA	6.5 MEDIUM	ADJACENT_NETWORK	LOW	NONE	CVSS:3.1/AV:A/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: 28%

Vendor	Product	Version
zyxel	usg_20w-vpn_firmware	4.16 ≤ 𝑥 < 5.37
zyxel	usg_2200-vpn_firmware	4.30 ≤ 𝑥 < 5.37
zyxel	usg_flex_100_firmware	4.50 ≤ 𝑥 < 5.37
zyxel	usg_flex_100w_firmware	4.50 ≤ 𝑥 < 5.37
zyxel	usg_flex_200_firmware	4.50 ≤ 𝑥 < 5.37
zyxel	usg_flex_50_firmware	4.50 ≤ 𝑥 < 5.37
zyxel	usg_flex_500_firmware	4.50 ≤ 𝑥 < 5.37
zyxel	usg_flex_50w_firmware	4.50 ≤ 𝑥 < 5.37
zyxel	usg_flex_700_firmware	4.50 ≤ 𝑥 < 5.37
zyxel	zywall_atp100_firmware	4.32 ≤ 𝑥 < 5.37
zyxel	zywall_atp100w_firmware	4.32 ≤ 𝑥 < 5.37
zyxel	zywall_atp200_firmware	4.32 ≤ 𝑥 < 5.37
zyxel	zywall_atp500_firmware	4.32 ≤ 𝑥 < 5.37
zyxel	zywall_atp700_firmware	4.32 ≤ 𝑥 < 5.37
zyxel	zywall_atp800_firmware	4.32 ≤ 𝑥 < 5.37
zyxel	zywall_vpn100_firmware	4.30 ≤ 𝑥 < 5.37
zyxel	zywall_vpn2s_firmware	4.30 ≤ 𝑥 < 5.37
zyxel	zywall_vpn300_firmware	4.30 ≤ 𝑥 < 5.37
zyxel	zywall_vpn50_firmware	4.30 ≤ 𝑥 < 5.37
zyxel	zywall_vpn_100_firmware	4.30 ≤ 𝑥 < 5.37
zyxel	zywall_vpn_300_firmware	4.30 ≤ 𝑥 < 5.37
zyxel	zywall_vpn_50_firmware	4.30 ≤ 𝑥 < 5.37
zyxel	nxc2500_firmware	6.10\(aaig.0\) ≤ 𝑥 ≤ 6.10\(aaig.3\)
zyxel	nxc5500_firmware	6.10\(aaos.0\) ≤ 𝑥 ≤ 6.10\(aaos.4\)

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-in-firewalls-and-wlan-controllers