CVE-2025-54989 is a vulnerability identified in the FirebirdSQL relational database system affecting versions prior to 3.0.13, 4.0.6, and 5.0.3. The flaw is due to improper handling of XDR (External Data Representation) messages sent from clients, specifically a NULL pointer dereference during message parsing. When a maliciously crafted XDR message is received, the server attempts to dereference a NULL pointer, leading to a crash and denial of service (DoS). This vulnerability is exploitable remotely without requiring authentication or user interaction, making it accessible to any attacker with network access to the FirebirdSQL server. The CVSS v3.1 base score is 5.3 (medium severity), reflecting the ease of exploitation and the impact limited to availability. No known exploits have been reported in the wild yet, but the vulnerability poses a risk to systems that rely on FirebirdSQL for critical data services. The issue has been addressed in FirebirdSQL versions 3.0.13, 4.0.6, and 5.0.3, where input validation and pointer checks have been improved to prevent the NULL dereference. Organizations running affected versions should upgrade promptly to avoid potential service disruptions.

The primary impact of CVE-2025-54989 is denial of service, causing FirebirdSQL database servers to crash and become unavailable. For European organizations, this can lead to downtime of applications and services dependent on FirebirdSQL, potentially disrupting business operations, customer services, and internal workflows. While the vulnerability does not compromise data confidentiality or integrity, loss of availability can affect sectors relying on real-time data processing, such as finance, healthcare, and manufacturing. Extended outages could result in financial losses, reputational damage, and regulatory compliance issues, especially under GDPR where service availability is critical. Organizations using FirebirdSQL in embedded systems or critical infrastructure may face operational risks. The lack of authentication requirement means attackers can exploit the vulnerability from any network location with access to the database port, increasing the attack surface. However, the absence of known exploits reduces immediate risk but should not lead to complacency.

1. Upgrade FirebirdSQL to versions 3.0.13, 4.0.6, or 5.0.3 or later, where the vulnerability is patched. 2. If immediate upgrade is not feasible, restrict network access to FirebirdSQL servers using firewalls or network segmentation to limit exposure to trusted clients only. 3. Implement intrusion detection systems (IDS) and network monitoring to detect anomalous or malformed XDR messages targeting the database. 4. Regularly audit and review database server logs for signs of crashes or unusual activity indicative of attempted exploitation. 5. Employ rate limiting or connection throttling on database ports to reduce the risk of DoS attacks. 6. Develop and test incident response plans to quickly recover from potential DoS events affecting FirebirdSQL services. 7. Coordinate with application teams to ensure fallback or redundancy mechanisms are in place to maintain service continuity during outages.