An issue was discovered in Mbed TLS 3.5.x before 3.6.0. When negotiating the TLS version on the server side, it can fall back to the TLS 1.2 implementation of the protocol if it is disabled. If the TLS 1.2 implementation was disabled at build time, a TLS 1.2 client could put a TLS 1.3-only server into an infinite loop processing a TLS 1.2 ClientHello, resulting in a denial of service. If the TLS 1.2 implementation was disabled at runtime, a TLS 1.2 client can successfully establish a TLS 1.2 connection with the server.
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mbed_tls | Arm | 3.5.0 (including) | 3.6.0 (excluding) |
| Mbedtls | Ubuntu | focal | * |
| Mbedtls | Ubuntu | mantic | * |