CVE-2023-6937

published 2024-02-15

CVE-2023-6937: 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…

Priority P4 27 medium 5.3 CVSS 3.1

AV N AC L PR N UI N S U C L I N A N

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.

Affected

10 ranges

Vendor	Product	Version range	Fixed in
debian	wolfssl	< wolfssl 5.6.6-1.2 (forky)	wolfssl 5.6.6-1.2 (forky)
msrc	azl3_mariadb_10.11.6-3_on_azure_linux_3.0	—	—
msrc	azure_linux_3.0_arm	—	—
msrc	azure_linux_3.0_x64	—	—
msrc	cbl_mariner_2.0_arm	—	—
msrc	cbl_mariner_2.0_x64	—	—
wolfssl	wolfssl	< 5.6.6	5.6.6
wolfssl	wolfssl	<= 5.6.4	—
wolfssl	wolfssl	>= 0 < 5.6.6-1.2	5.6.6-1.2
wolfssl	wolfssl	>= 0 < 5.6.6-1.2	5.6.6-1.2

CVSS provenance

nvd v3.1 5.3 MEDIUM CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

osv 5.3 MEDIUM

vendor_debian 5.3 MEDIUM

vendor_msrc 5.3 MEDIUM

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CWE-20