CVE Vulnerabilities

CVE-2019-11690

Use of Insufficiently Random Values

Published: May 03, 2019 | Modified: May 06, 2019
CVSS 3.x
5.9
MEDIUM
Source:
NVD
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu

gen_rand_uuid in lib/uuid.c in Das U-Boot v2014.04 through v2019.04 lacks an srand call, which allows attackers to determine UUID values in scenarios where CONFIG_RANDOM_UUID is enabled, and Das U-Boot is relied upon for UUID values of a GUID Partition Table of a boot device.

Weakness

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

Affected Software

Name Vendor Start Version End Version
U-boot Denx 2014.04 2019.04
U-boot Ubuntu cosmic *
U-boot Ubuntu disco *
U-boot Ubuntu esm-infra/xenial *
U-boot Ubuntu upstream *
U-boot Ubuntu xenial *

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