CVE-2023-6937

Publication date 15 February 2024

Last updated 26 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

5.3 · Medium

Score breakdown

Description

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.

Status

Package Ubuntu Release Status
wolfssl 26.04 LTS resolute
Not affected
25.10 questing
Not affected
25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic Ignored end of life, was needs-triage
23.04 lunar Ignored end of life, was needs-triage
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty Not in release

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.3 · Medium

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

References

Other references

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