# CVE-2021-46823: python-ldap: python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitio...

CVE-2021-46823 is fixed in 4 products on 1 platform, first by python-ldap 3.0.0-1ubuntu0.2, released June 18, 2022. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-46823
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0197
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 18, 2022

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-ldap Debian 12.15 (bookworm) | 3.4.0-1 | [DEBIAN-CVE-2021-46823](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46823.md) | Jun 18, 2022 |
| Linux | python-ldap Debian 13.5 (trixie) | 3.4.0-1 | [DEBIAN-CVE-2021-46823](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46823.md) | Jun 18, 2022 |
| Linux | python-ldap Debian 14 | 3.4.0-1 | [DEBIAN-CVE-2021-46823](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46823.md) | Jun 18, 2022 |
| Linux | python-ldap Ubuntu 18.04.6 LTS (bionic) | 3.0.0-1ubuntu0.2 | [python-ldap 3.0.0-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-ldap-3.0.0-1ubuntu0.2.md) | Jun 18, 2022 |
| Linux | python-pyldap Ubuntu 18.04.6 LTS (bionic) | 3.0.0-1ubuntu0.2 | [python-pyldap 3.0.0-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-pyldap-3.0.0-1ubuntu0.2.md) | Jun 18, 2022 |
| Linux | python3-ldap Ubuntu 18.04.6 LTS (bionic) | 3.0.0-1ubuntu0.2 | [python3-ldap 3.0.0-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-ldap-3.0.0-1ubuntu0.2.md) | Jun 18, 2022 |
| Linux | python3-ldap Ubuntu 20.04 LTS (focal) | 3.2.0-4ubuntu2.1 | [python3-ldap 3.2.0-4ubuntu2.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-ldap-3.2.0-4ubuntu2.1.md) | Jun 18, 2022 |
| Linux | python3-ldap Ubuntu 22.04.1 LTS (jammy) | 3.2.0-4ubuntu7.1 | [python3-ldap 3.2.0-4ubuntu7.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-ldap-3.2.0-4ubuntu7.1.md) | Jun 18, 2022 |
| Linux | python3-pyldap Ubuntu 18.04.6 LTS (bionic) | 3.0.0-1ubuntu0.2 | [python3-pyldap 3.0.0-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-pyldap-3.0.0-1ubuntu0.2.md) | Jun 18, 2022 |
| Linux | python3-pyldap Ubuntu 20.04 LTS (focal) | 3.2.0-4ubuntu2.1 | [python3-pyldap 3.2.0-4ubuntu2.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-pyldap-3.2.0-4ubuntu2.1.md) | Jun 18, 2022 |
| Linux | python3-pyldap Ubuntu 22.04.1 LTS (jammy) | 3.2.0-4ubuntu7.1 | [python3-pyldap 3.2.0-4ubuntu7.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-pyldap-3.2.0-4ubuntu7.1.md) | Jun 18, 2022 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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