Firebird has Pre-Auth DOS when Processing Out of Order CNCT_specific_data Segments
Summary
Firebird has Pre-Auth DOS when Processing Out of Order CNCT_specific_data Segments
Original description
The description as published by the source.
Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, when processing CNCT_specific_data segments during authentication, the server assumes segments arrive in strictly ascending order. If segments arrive out of order, the Array class's grow() method computes a negative size value, causing a SIGSEGV crash. An unauthenticated attacker who knows only the server's IP and port can exploit this to crash the server. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-27890 firebird3.0
- Ubuntu UBUNTU-CVE-2026-27890 firebird3.0
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- web github.com
- web github.com
- web github.com