What is the CVSS score of CVE-2023-35943?

CVE-2023-35943 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.6%.

Is there a public PoC exploit available for CVE-2023-35943?

Yes, a public proof-of-concept exploit is available for CVE-2023-35943. Prioritise patching immediately. EPSS: 0.6%.

Envoy CVE-2023-35943

HIGH

Use After Free (CWE-416)

2023-07-25 security-advisories@github.com

Use After Free Denial Of Service Memory Corruption Envoy

7.5

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.5 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

CVE Published

Jul 25, 2023 - 19:15 nvd

HIGH 7.5

DescriptionNVD

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, the CORS filter will segfault and crash Envoy when the origin header is removed and deleted between decodeHeadersand encodeHeaders. Versions 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, do not remove the origin header in the Envoy configuration.

AnalysisAI

Envoy is an open source edge and service proxy designed for cloud-native applications. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. 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, the CORS filter will segfault and crash Envoy when the origin header is removed and deleted between decodeHeadersand encodeHeaders. Versions 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, do not remove the origin header in the Envoy configuration. Affected products include: Envoyproxy Envoy.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.