The DNS client in Microsoft Windows 2000 SP4, XP SP2, Server 2003 SP1 and SP2, and Vista uses predictable DNS transaction IDs, which allows remote attackers to spoof DNS responses.
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 |
| Windows_2000 |
Microsoft |
- |
- |
| Windows_server_2003 |
Microsoft |
- |
- |
| Windows_server_2003 |
Microsoft |
- |
- |
| Windows_vista |
Microsoft |
- |
- |
| Windows_xp |
Microsoft |
- |
- |
| Windows_xp |
Microsoft |
- |
- |
| Windows_xp |
Microsoft |
- |
- |
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