What is the CVSS score of CVE-2021-39534?

CVE-2021-39534 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 1.2%.

Is there a public PoC exploit available for CVE-2021-39534?

Yes, a public proof-of-concept exploit is available for CVE-2021-39534. Prioritise patching immediately. EPSS: 1.2%.

Libslax CVE-2021-39534

HIGH

Out-of-bounds Write (CWE-787)

2021-09-20 cve@mitre.org

Buffer Overflow Memory Corruption Libslax

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Sep 20, 2021 - 16:15 nvd

HIGH 8.8

DescriptionNVD

An issue was discovered in libslax through v0.22.1. slaxIsCommentStart() in slaxlexer.c has a heap-based buffer overflow.

AnalysisAI

An issue was discovered in libslax through v0.22.1. Rated high severity (CVSS 8.8), 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 Out-of-bounds Write (CWE-787), which allows attackers to write data beyond allocated buffer boundaries leading to code execution or crashes. An issue was discovered in libslax through v0.22.1. slaxIsCommentStart() in slaxlexer.c has a heap-based buffer overflow. Affected products include: Juniper Libslax.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate write boundaries, use memory-safe languages, enable compiler protections (ASLR, stack canaries).