CVE-2023-6936 - CVE House
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Status published Medium CVE-2023-6936

Heap-buffer over-read with WOLFSSL_CALLBACKS

Vulnerability Description

In wolfSSL prior to 5.6.6, if callback functions are enabled (via the WOLFSSL_CALLBACKS flag), then a malicious TLS client or network attacker can trigger a buffer over-read on the heap of 5 bytes (WOLFSSL_CALLBACKS is only intended for debugging).

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Lucca Hirschi (Inria, LORIA)
  • Steve Kremer (Inria, LORIA)
  • Max Ammann (Trail of Bits)
  • tlspuffin

References

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Affected Vendor

Affected Software

wolfSSL
Vulnerable Versions:
0

Timeline

Official Publish: February 20th, 2024
Last Modified: March 26th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.