CVE Vulnerabilities

CVE-2020-27633

Use of Insufficiently Random Values

Published: Oct 10, 2023 | Modified: Oct 13, 2023
CVSS 3.x
9.1
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

In FNET 4.6.3, TCP ISNs are improperly random.

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
Fnet Butok 4.6.3 (including) 4.6.3 (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.

References