Cyber Resilience

CVE-2023-34140

Medium

Published: 17 July 2023

Published
17 July 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0014 33.4th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-34140 is a medium-severity Classic Buffer Overflow (CWE-120) vulnerability in Zyxel Usg 20W-Vpn Firmware. Its CVSS base score is 6.5 (Medium).

Operationally, ranked at the 33.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

zyxel
usg 20w-vpn firmware
4.16 — 5.37
zyxel
usg 2200-vpn firmware
4.30 — 5.37
zyxel
usg flex 100 firmware
4.50 — 5.37
zyxel
usg flex 100w firmware
4.50 — 5.37
zyxel
usg flex 200 firmware
4.50 — 5.37
zyxel
usg flex 50 firmware
4.50 — 5.37
zyxel
usg flex 500 firmware
4.50 — 5.37
zyxel
usg flex 50w firmware
4.50 — 5.37
zyxel
usg flex 700 firmware
4.50 — 5.37
zyxel
zywall atp100 firmware
4.32 — 5.37
+14 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-120

Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.

References