An insecure random number generation vulnerability in BlaB! AX, BlaB! AX Pro, BlaB! WS (client), and BlaB! WS Pro (client) version 19.11 allows an attacker (with a guest or user session cookie) to escalate privileges by retrieving the cookie salt value and creating a valid session cookie for an arbitrary user or admin.
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 |
|---|---|---|---|
| Blab!_ax | Justblab | 19.11 (including) | 19.11 (including) |
| Blab!_ax_pro | Justblab | 19.11 (including) | 19.11 (including) |
| Blab!_ws | Justblab | 19.11 (including) | 19.11 (including) |
| Blab!_ws_pro | Justblab | 19.11 (including) | 19.11 (including) |
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.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/112.html
- https://cwe.mitre.org/data/definitions/485.html
- https://cwe.mitre.org/data/definitions/59.html