CVE Vulnerabilities

CVE-2021-44151

Use of Insufficiently Random Values

Published: Dec 13, 2021 | Modified: Aug 08, 2023
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu

An issue was discovered in Reprise RLM 14.2. As the session cookies are small, an attacker can hijack any existing sessions by bruteforcing the 4 hex-character session cookie on the Windows version (the Linux version appears to have 8 characters). An attacker can obtain the static part of the cookie (cookie name) by first making a request to any page on the application (e.g., /goforms/menu) and saving the name of the cookie sent with the response. The attacker can then use the name of the cookie and try to request that same page, setting a random value for the cookie. If any user has an active session, the page should return with the authorized content, when a valid cookie value is hit.

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
Reprise_license_manager Reprisesoftware 14.2 (including) 14.2 (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