CVE-2023-3724

TLS 1.3 client issue handling malicious server when not including a KSE and PSK extension

Description

If a TLS 1.3 client gets neither a PSK (pre shared key) extension nor a KSE (key share extension) when connecting to a malicious server, a default predictable buffer gets used for the IKM (Input Keying Material) value when generating the session master secret. Using a potentially known IKM value when generating the session master secret key compromises the key generated, allowing an eavesdropper to reconstruct it and potentially allowing access to or meddling with message contents in the session. This issue does not affect client validation of connected servers, nor expose private key information, but could result in an insecure TLS 1.3 session when not controlling both sides of the connection. wolfSSL recommends that TLS 1.3 client side users update the version of wolfSSL used. 

Remediation

Solution:

  • Fixed in the following GitHub pull request https://github.com/wolfSSL/wolfssl/pull/6412 https://github.com/wolfSSL/wolfssl/pull/6412

Categories

9.1
CVSS
Severity: Critical
CVSS 3.1 •
EPSS 0.10%
Vendor Advisory wolfssl.com
Affected: wolfSSL wolfSSL
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2023-3724?
CVE-2023-3724 has been scored as a critical severity vulnerability.
How to fix CVE-2023-3724?
To fix CVE-2023-3724: Fixed in the following GitHub pull request https://github.com/wolfSSL/wolfssl/pull/6412 https://github.com/wolfSSL/wolfssl/pull/6412
Is CVE-2023-3724 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-3724 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-3724?
CVE-2023-3724 affects wolfSSL wolfSSL.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.