CVE-2021-4248

A vulnerability was found in kapetan dns up to 6.1.0. It has been rated as problematic. Affected by this issue is some unknown functionality of the file DNS/Protocol/Request.cs. The manipulation leads to insufficient entropy in prng. The attack may be launched remotely. Upgrading to version 7.0.0 is able to address this issue. The name of the patch is cf7105aa2aae90d6656088fe5a8ee1d5730773b6. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-216188.

Weakness

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Affected Software

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

References

• https://github.com/kapetan/dns/commit/cf7105aa2aae90d6656088fe5a8ee1d5730773b6
• https://github.com/kapetan/dns/pull/88
• https://github.com/kapetan/dns/releases/tag/v7.0.0
• https://vuldb.com/?id.216188