CVE-2025-24975: Firebird is a relational database. Prior to snapshot versions 4.0.6.3183, 5.0.2.1610, and 6.0.0.609, Firebird is vulnerable if ExtConnPoolSize is not ...

Description

Firebird is a relational database. Prior to snapshot versions 4.0.6.3183, 5.0.2.1610, and 6.0.0.609, Firebird is vulnerable if ExtConnPoolSize is not set equal to 0. If connections stored in ExtConnPool are not verified for presence and suitability of the CryptCallback interface is used when created versus what is available could result in a segfault in the server process. Encrypted databases, accessed by execute statement on external, may be accessed later by an attachment missing a key to that database. In a case when execute statement are chained, segfault may happen. Additionally, the segfault may affect unencrypted databases. This issue has been patched in snapshot versions 4.0.6.3183, 5.0.2.1610, and 6.0.0.609 and point releases 4.0.6 and 5.0.2. A workaround for this issue involves setting ExtConnPoolSize equal to 0 in firebird.conf.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.47%

37.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-754

Affected Software

Vendor	Product	Versions
Firebirdsql	Firebird	>= 4.0.0, < 4.0.6
Firebirdsql	Firebird	>= 5.0.0, < 5.0.2

References

https://github.com/FirebirdSQL/firebird/commit/658abd20449f72097fbbce57e8e6ae42ff837fb6Patch
https://github.com/FirebirdSQL/firebird/issues/8429Issue Tracking
https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-fx9r-rj68-7p69Mitigation, Vendor Advisory
https://www.vicarius.io/vsociety/posts/cve-2025-24975-detect-vulnerable-firebirdExploit, Third Party Advisory
https://www.vicarius.io/vsociety/posts/cve-2025-24975-mitigate-firebird-vulnerabilityExploit, Third Party Advisory

Timeline

Published: Aug 15, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-24975?

Firebird is a relational database. Prior to snapshot versions 4.0.6.3183, 5.0.2.1610, and 6.0.0.609, Firebird is vulnerable if ExtConnPoolSize is not set equal to 0. If connections stored in ExtConnPool are not verified for presence and suitability of the CryptCallback interface is used when created versus what is available could result in a segfault in the server process. Encrypted databases, accessed by execute statement on external, may be accessed later by an attachment missing a key to that database. In a case when execute statement are chained, segfault may happen. Additionally, the segfault may affect unencrypted databases. This issue has been patched in snapshot versions 4.0.6.3183, 5.0.2.1610, and 6.0.0.609 and point releases 4.0.6 and 5.0.2. A workaround for this issue involves setting ExtConnPoolSize equal to 0 in firebird.conf.

How severe is CVE-2025-24975?

CVE-2025-24975 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.47% probability of exploitation in the next 30 days.

How do I fix CVE-2025-24975?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.