Critical severity · published Feb 20, 2024
CVE-2023-6936
Heap-buffer over-read with WOLFSSL_CALLBACKS
9.1
CVSS
0.6%
EPSS
No
On KEV
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).
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 49% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WO
wolfSSL · wolfSSL
through 5.6.5 · source: vendor, NVD, CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-6936
CVE.org
https://www.cve.org/CVERecord?id=CVE-2023-6936
Issue Tracking
https://github.com/wolfSSL/wolfssl/pull/6949/
Vendor Advisory
https://www.wolfssl.com/docs/security-vulnerabilities/
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