PT-2021-24339 · Unknown+3 · Python-Ldap+3

Encukou · CVE-2021-46823 · Published 2021-11-29 · Updated 2026-07-06

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions: python-ldap versions prior to 3.4.0

Description: The issue is related to 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. This occurs when ldap.schema is used for untrusted schema definitions.

Recommendations: For versions prior to 3.4.0, as a temporary workaround, consider checking input for an excessive amount of backslashes in schemas, as more than a dozen backslashes per line are atypical. Update to version 3.4.0 or later, which contains a workaround to prevent ReDoS attacks by refusing schema definitions with an excessive amount of backslashes.

Fix

DoS

Weakness Enumeration

CWE-1333

Related Identifiers

AZL-9960

CVE-2021-46823

GHSA-QFR5-WJPW-Q4C4

GHSA-R8WQ-QRXC-HMCM

MGASA-2022-0310

OESA-2022-1792

OESA-2022-1809

PYSEC-2026-912

USN-5508-1

Affected Products

Debian

Linuxmint

Ubuntu

Python-Ldap

References · 28

• https://cve.org/CVERecord?id=CVE-2021-46823 · Security Note
• https://osv.dev/vulnerability/CVE-2021-46823 · Vendor Advisory
• https://osv.dev/vulnerability/AZL-9960 · Vendor Advisory
• https://osv.dev/vulnerability/MGASA-2022-0310 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-46823 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-qfr5-wjpw-q4c4 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-46823 · Vendor Advisory
• https://advisories.mageia.org/MGASA-2022-0310.html · Security Note
• https://osv.dev/vulnerability/USN-5508-1 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-r8wq-qrxc-hmcm · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-46823 · Vendor Advisory
• https://osv.dev/vulnerability/PYSEC-2026-912 · Vendor Advisory
• https://osv.dev/vulnerability/OESA-2022-1809 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-46823 · Security Note
• https://osv.dev/vulnerability/OESA-2022-1792 · Vendor Advisory