Is CVE-2023-34140 in the CISA KEV catalog?

No. CVE-2023-34140 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2023-34140?

CVE-2023-34140 has a CVSS v3 base score of 6.5 (MEDIUM).

What is the EPSS score for CVE-2023-34140?

CVE-2023-34140 has an EPSS score of 0.27% (18th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2023-34140?

Upgrade usg 20w-vpn firmware to 5.37 or later. Fixes are available for 22 affected products.

CVE & CISA-KEV Catalog

CVE-2023-34140

MEDIUM

6.5

CVSS v3

NVD

Description

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.

CWE-120Classic Buffer Overflow

How to fix

Remediation Available

usg 20w-vpn firmwareNVD

Affected:>= 4.16, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

usg 2200-vpn firmwareNVD

Affected:>= 4.30, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

usg flex 100 firmwareNVD

Affected:>= 4.50, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

usg flex 100w firmwareNVD

Affected:>= 4.50, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

usg flex 200 firmwareNVD

Affected:>= 4.50, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

usg flex 500 firmwareNVD

Affected:>= 4.50, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

usg flex 50 firmwareNVD

Affected:>= 4.50, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

usg flex 50w firmwareNVD

Affected:>= 4.50, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

usg flex 700 firmwareNVD

Affected:>= 4.50, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall atp100 firmwareNVD

Affected:>= 4.32, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall atp100w firmwareNVD

Affected:>= 4.32, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall atp200 firmwareNVD

Affected:>= 4.32, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall atp500 firmwareNVD

Affected:>= 4.32, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall atp700 firmwareNVD

Affected:>= 4.32, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall atp800 firmwareNVD

Affected:>= 4.32, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall vpn100 firmwareNVD

Affected:>= 4.30, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall vpn2s firmwareNVD

Affected:>= 4.30, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall vpn300 firmwareNVD

Affected:>= 4.30, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall vpn50 firmwareNVD

Affected:>= 4.30, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall vpn 100 firmwareNVD

Affected:>= 4.30, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall vpn 300 firmwareNVD

Affected:>= 4.30, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

zywall vpn 50 firmwareNVD

Affected:>= 4.30, < 5.37Fixed in:5.37CVE-2023-34140derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorAdjacent

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.27%probability of exploitation in 30 days

18thpercentile

Low risk: more likely to be exploited than 18% of all known CVEs.

References

Vendor Advisory1

zyxel.com

Related Vulnerabilities

Other CWE-120 (Classic Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2014-0195	Medium	6.8	100%	-	Fix
CVE-2017-7269	Critical	9.8	100%	KEV	-
CVE-2019-11043	High	8.7	99%	KEV + Ransom	Fix
CVE-2011-4862	High	10.0	95%	-	Fix
CVE-2007-5659	High	7.8	94%	KEV	Fix
CVE-2022-3786	High	7.5	91%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.