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TI-2023-03477 Aliases CVE-2023-3724GHSA-h4rv-393v-2f5h

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

Priority MEDIUM 42CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-295.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00652 51st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
wolfSSLwolfSSL3.14.0 – 5.6.0—No fix listedCNA
  • wolfSSL VendorwolfSSL Affected 3.14.0 – 5.6.0 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*before 5.6.2VulnerablewolfSSL
  • cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:* Versions before 5.6.2 Vulnerable ·wolfSSL

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-3724
  2. 2026-10-03 Alias added: GHSA-h4rv-393v-2f5h
  3. 2026-10-14 EPSS moved to the 50th–90th percentile

References

Patch 1

Advisory 1

  • TI-2024-00830 SEGV and out of bounds memory read from malicious packet CVSS 3.1CRITICAL 9.1
  • TI-2022-18557 In wolfSSL before 5.5.1, malicious clients can cause a buffer overflow during a TLS 1.3… CVSS 3.1HIGH 7.5
  • TI-2025-10943 Potential DoS Vulnerability through Multiple KeyShareEntry with Same Group in TLS 1.3 ClientHello CVSS 4.0MEDIUM 6.3
  • TI-2017-09737 wolfSSL Bleichenbacher/ROBOT CVSS 3.0HIGH 7.5
  • TI-2019-08902 wolfSSL 4.0.0 has a Buffer Overflow in DoPreSharedKeys in tls13.c when a current identity… CVSS 3.1CRITICAL 9.8
  • TI-2017-02021 Improper certificate validation in wolfSSL CVSS 3.1CRITICAL 9.8
See all 150 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences