CVE-2025-24975
Firebirdsql Firebird 4.0.0 – 4.0.6
Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:LSummary
CVE-2025-24975 is a high-severity Improper Check for Unusual or Exceptional Conditions (CWE-754) vulnerability in Firebirdsql Firebird. Its CVSS base score is 7.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Service Stop (T1489); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-24975 is a vulnerability in Firebird, an open-source relational database server, affecting versions prior to snapshot builds 4.0.6.3183, 5.0.2.1610, and 6.0.0.609 when the ExtConnPoolSize configuration parameter is not set to 0. The issue stems from external connection pool (ExtConnPool) entries not being verified for the presence and suitability of the CryptCallback interface relative to conditions at creation time. This mismatch can trigger a segmentation fault (segfault) in the server process, particularly during chained execute statements on external connections. Encrypted databases accessed via such statements may subsequently be reachable by attachments lacking the encryption key, enabling unauthorized access, while the segfault can also impact unencrypted databases. The vulnerability carries a CVSS v3.1 base score of 7.1 (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L) and maps to CWE-754 (Improper Check for Unusual or Exceptional Conditions).
A low-privileged user (PR:L) with network access can exploit this over the network (AV:N), though it requires high attack complexity (AC:H) and no user interaction. By issuing execute statements on external connections in a configuration where ExtConnPoolSize exceeds 0, the attacker can induce a server segfault for denial-of-service impact (A:L). Attackers may also gain high confidentiality (C:H) and integrity (I:H) effects by accessing encrypted database contents without the required key via pooled connections reused by unauthorized attachments.
Firebird has patched the vulnerability in snapshot versions 4.0.6.3183, 5.0.2.1610, and 6.0.0.609, as well as point releases 4.0.6 and 5.0.2. A recommended workaround is to set ExtConnPoolSize to 0 in the firebird.conf file. Official advisories, including the fixing commit, issue discussion, and GitHub security advisory, provide further details on the patch and verification steps.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-25030
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 7 hardening rules · 2 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation explicitly exercises unusual conditions to find missing or incorrect checks.
Input validation directly requires checking for unexpected or malformed conditions before they propagate.
Security engineering principles include structured handling of edge cases and exceptions during design.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure development practices directly require proper checks and handling for exceptional conditions throughout the SDLC.
Runtime monitoring of software and environments can detect adverse events triggered by unhandled exceptional conditions.
Generating logs of exceptions and errors enables detection of improper handling of unusual conditions.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development and acceptance verifies handling of error and exceptional conditions.
Logging can record unhandled exceptions but does not prevent the weakness itself.
Monitoring may detect symptoms of unhandled conditions but does not eliminate the root weakness.
Secure development life cycle mandates exception handling and input validation that directly prevent missing checks for unusual conditions.
Application security requirements explicitly call for handling of exceptional conditions and error paths.
Secure system architecture and engineering principles require robust error and exception handling mechanisms.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-754
- V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-754
Oracle Linux 9 (1 rule)
- V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-754