CVE Vulnerabilities

CVE-2021-22948

Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Published: Sep 23, 2021 | Modified: Jun 30, 2023
CVSS 3.x
7.1
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/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

Vulnerability in the generation of session IDs in revive-adserver < 5.3.0, based on the cryptographically insecure uniqid() PHP function. Under some circumstances, an attacker could theoretically be able to brute force session IDs in order to take over a specific account.

Weakness

The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG’s algorithm is not cryptographically strong.

Affected Software

Name Vendor Start Version End Version
Revive_adserver Revive-adserver * 5.3.0 (excluding)
Revive_adserver Revive-adserver 5.3.0-rc1 (including) 5.3.0-rc1 (including)

Extended Description

When a non-cryptographic PRNG is used in a cryptographic context, it can expose the cryptography to certain types of attacks. Often a pseudo-random number generator (PRNG) is not designed for cryptography. Sometimes a mediocre source of randomness is sufficient or preferable for algorithms that use random numbers. Weak generators generally take less processing power and/or do not use the precious, finite, entropy sources on a system. While such PRNGs might have very useful features, these same features could be used to break the cryptography.

Potential Mitigations

References