Cyber Resilience

CVE-2023-33011

Zyxel Usg 2200-Vpn Firmware 5.00 – 5.37

Published
17 July 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0034 27th percentile
Risk Priority 63 floored blend · peak EPSS

Summary

CVE-2023-33011 is a high-severity Use of Externally-Controlled Format String (CWE-134) vulnerability in Zyxel Usg 2200-Vpn Firmware. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 27th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

A format string vulnerability in the Zyxel ATP series firmware versions 5.10 through 5.36 Patch 2, USG FLEX series firmware versions 5.00 through 5.36 Patch 2, USG FLEX 50(W) series firmware versions 5.10 through 5.36 Patch 2, USG20(W)-VPN series firmware…

more

versions 5.10 through 5.36 Patch 2, and VPN series firmware versions 5.00 through 5.36 Patch 2, could allow an unauthenticated, LAN-based attacker to execute some OS commands by using a crafted PPPoE configuration on an affected device when the cloud management mode is enabled.

CWE(s)
CWE-134

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-34140Same product: Zyxel Usg 20W-Vpn
CVE-2023-6764Same product: Zyxel Usg Flex 100
CVE-2023-6399Same product: Zyxel Usg Flex 100
CVE-2023-28767Same product: Zyxel Usg 20W-Vpn
CVE-2023-33012Same product: Zyxel Usg 20W-Vpn
CVE-2023-34138Same product: Zyxel Usg 20W-Vpn
CVE-2023-22923Same vendor: Zyxel
CVE-2023-34141Same product: Zyxel Usg 20W-Vpn
CVE-2023-34139Same product: Zyxel Usg 2200-Vpn
CVE-2023-22915Same product: Zyxel Usg 20W-Vpn

Affected Assets

zyxel
usg 2200-vpn firmware
5.00 — 5.37
zyxel
usg flex 100 firmware
5.00 — 5.37
zyxel
usg flex 100w firmware
5.00 — 5.37
zyxel
usg flex 200 firmware
5.00 — 5.37
zyxel
usg flex 50 firmware
5.00 — 5.37
zyxel
usg flex 500 firmware
5.00 — 5.37
zyxel
usg flex 50w firmware
5.00 — 5.37
zyxel
usg flex 700 firmware
5.00 — 5.37
zyxel
zywall vpn100 firmware
5.00 — 5.37
zyxel
zywall vpn2s firmware
5.00 — 5.37
+12 more product configuration(s) — see NVD for full list

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent external format strings via code review, static analysis, and safe APIs.

ID.RA-01 partial match
prevents

Vulnerability identification can discover existing format-string flaws but does not prevent their introduction.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect format-string vulnerabilities before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and safe API usage that can prevent externally-controlled format strings.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify safe formatting functions and ban uncontrolled format strings.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles discourage dangerous string-handling patterns that lead to format-string issues.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly forbid the use of untrusted format strings and prescribe safe alternatives.

References