// For flags

CVE-2023-6937

Improper (D)TLS key boundary enforcement

Severity Score

5.3
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Attend
*SSVC
Descriptions

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.

wolfSSL anterior a 5.6.6 no verificaba que los mensajes en un registro (D)TLS no abarquen límites clave. Como resultado, fue posible combinar mensajes (D)TLS usando diferentes claves en un registro (D)TLS. El caso más extremo es que, en (D)TLS 1.3, era posible que un registro (D)TLS 1.3 no cifrado del servidor que contuviera primero un mensaje ServerHello y luego el resto del primer vuelo del servidor fuera aceptado por un wolfSSL. cliente. En (D)TLS 1.3, el protocolo de enlace se cifra después de ServerHello, pero un cliente wolfSSL aceptaría un vuelo sin cifrar desde el servidor. Esto no compromete la negociación y autenticación de claves, por lo que se le asigna una calificación de gravedad baja.

*Credits: Johannes Wilson from Sectra Communications and Linköping University
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Attend
Exploitation
None
Automatable
Yes
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2023-12-18 CVE Reserved
  • 2024-02-15 CVE Published
  • 2024-02-16 EPSS Updated
  • 2024-08-02 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-20: Improper Input Validation
CAPEC
  • CAPEC-272: Protocol Manipulation
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
WolfSSL
Search vendor "WolfSSL"
WolfSSL
Search vendor "WolfSSL" for product "WolfSSL"
<= 5.6.4
Search vendor "WolfSSL" for product "WolfSSL" and version " <= 5.6.4"
en
Affected