Non-random values for ticket_age_add in session tickets in crypto/tls before Go 1.17.11 and Go 1.18.3 allow an attacker that can observe TLS handshakes to correlate successive connections by comparing ticket ages during session resumption.
Weakness
The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Go |
Golang |
* |
1.17.11 (excluding) |
| Go |
Golang |
1.18.0 (including) |
1.18.3 (excluding) |
Potential Mitigations
- Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds.
- In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts.
- Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a “random enough” number.
References