Cyber Resilience

CVE-2023-37926

Memory Safety in Zyxel Zld 4.32 – 5.37

Published
28 November 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0022 13th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2023-37926 is a medium-severity Classic Buffer Overflow (CWE-120) vulnerability in Zyxel Zld. Its CVSS base score is 5.5 (Medium).

Operationally, ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

A buffer overflow vulnerability in the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN…

more

series firmware versions 4.30 through 5.37, could allow an authenticated local attacker to cause denial-of-service (DoS) conditions by executing the CLI command to dump system logs on an affected device.

CWE(s)

Related Threats

CVEs Like This One

CVE-2023-4397Same product: Zyxel Atp100
CVE-2024-6343Same product: Zyxel Atp100
CVE-2023-35139Same product: Zyxel Atp100
CVE-2023-5650Same product: Zyxel Atp100
CVE-2023-35136Same product: Zyxel Atp100
CVE-2023-4398Same product: Zyxel Atp100
CVE-2023-22917Same product: Zyxel Atp100
CVE-2023-22915Same product: Zyxel Usg 20W-Vpn
CVE-2023-33010Same product: Zyxel Atp100
CVE-2023-33009Same product: Zyxel Atp100

Affected Assets

zyxel
zld
4.32 — 5.37 · 4.50 — 5.37 · 4.16 — 5.37

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.2.1

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.

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 development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.

ID.RA-01 partial match
prevents

Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.

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.

prevents

Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.

detects

Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.

prevents

Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.

prevents

Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.

prevents

Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.

References