Security 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 26th percentile
Risk Priority 63 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

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 LSASS Memory (T1003.001); ranked at the 26th 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

T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.002 Security Account Manager Credential Access
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored.
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.007 Proc Filesystem Credential Access
Adversaries may gather credentials from the proc filesystem or `/proc`.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1016 System Network Configuration Discovery Discovery
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
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-2023-34138Same product: Zyxel Usg 20W-Vpn
CVE-2023-33012Same 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.

ID.RA-01 partial match
blocks

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

PR.PS-06 partial match
blocks

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

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.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References