Cyber Resilience

CVE-2023-35942

Memory Safety in Envoyproxy Envoy 1.23.0 – 1.23.12

Public PoCMemory Safety
Published
25 July 2023
Modified
21 November 2024
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0089 56th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2023-35942 is a medium-severity Use After Free (CWE-416) vulnerability in Envoyproxy Envoy. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 44% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, gRPC access loggers using listener's global scope can cause a `use-after-free` crash when the listener is drained. Versions…

more

1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, disable gRPC access log or stop listener update.

CWE(s)

Related Threats

CVEs Like This One

CVE-2026-26330Same product: Envoyproxy Envoy
CVE-2025-54588Same product: Envoyproxy Envoy
CVE-2026-26311Same product: Envoyproxy Envoy
CVE-2026-48090Same product: Envoyproxy Envoy
CVE-2024-32974Same product: Envoyproxy Envoy
CVE-2024-39305Same product: Envoyproxy Envoy
CVE-2026-47207Same product: Envoyproxy Envoy
CVE-2024-23322Same product: Envoyproxy Envoy
CVE-2026-47205Same product: Envoyproxy Envoy
CVE-2023-35943Same product: Envoyproxy Envoy

Affected Assets

envoyproxy
envoy
1.23.0 — 1.23.12 · 1.24.0 — 1.24.10 · 1.25.0 — 1.25.9

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.3

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-416

Use-after-free exploits that achieve arbitrary code execution are blocked or significantly hardened by non-executable pages and ASLR.

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 incorporate memory-safety tooling and reviews that prevent most use-after-free defects.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover use-after-free issues via scanning or analysis but do not prevent their introduction.

PR.PS-02 partial match
prevents

Routine patching removes known use-after-free instances after they have been introduced in released software.

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.

detects

Security testing in development can detect use-after-free bugs before release.

prevents

Secure SDLC mandates memory-safety practices that reduce use-after-free defects.

prevents

Application security requirements can specify memory-management rules that mitigate use-after-free.

prevents

Secure architecture principles include memory-safety design choices that limit use-after-free exposure.

prevents

Secure coding standards directly prescribe avoidance of use-after-free patterns.

prevents

Change-management processes help ensure memory-safety fixes are deployed consistently.

References