CVE-2023-6937
mediumpriority · track · 21EPSS 0.005 · 44 %ileEUUSEPSS · scored 2026-10-27
wolfSSL prior to 5.6.6 did not check that messages in one (D)TLS record do not span key boundaries. As a result, it was possible to combine (D)TLS messages using different keys into one (D)TLS record. The most extreme edge case is that, in (D)TLS 1.3, it was possible that an unencrypted (D)TLS 1.3 record from the server containing first a ServerHello message and then the rest of the first server flight would be accepted by a wolfSSL client. In (D)TLS 1.3 the handshake is encrypted after the ServerHello but a wolfSSL client would accept an unencrypted flight from the server. This does not compromise key negotiation and authentication so it is assigned a low severity rating.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (7)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2023-6937/cnnvd
- https://github.com/wolfSSL/wolfssl/pull/7029cnnvd
- https://www.wolfssl.com/docs/security-vulnerabilities/cnnvd
- https://github.com/wolfSSL/wolfssl/pull/7029enisa_euvd
- https://www.wolfssl.com/docs/security-vulnerabilities/enisa_euvd
- https://github.com/wolfSSL/wolfssl/pull/7029Issue TrackingPatchnvd
- https://www.wolfssl.com/docs/security-vulnerabilities/Vendor Advisorynvd
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