CVE Vulnerabilities

CVE-2021-46823

Inefficient Regular Expression Complexity

Published: Jun 18, 2022 | Modified: Aug 08, 2023
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
4 MEDIUM
AV:N/AC:L/Au:S/C:N/I:N/A:P
RedHat/V2
RedHat/V3
Ubuntu

python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition.

Weakness

The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.

Affected Software

Name Vendor Start Version End Version
Python-ldap Python-ldap * 3.4.0 (excluding)

Extended Description

      Attackers can create crafted inputs that
      intentionally cause the regular expression to use
      excessive backtracking in a way that causes the CPU
      consumption to spike.

Potential Mitigations

References