{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-33337/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":7.5,"id":"CVE-2026-33337"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["critical"],"_cs_tags":["cve-2026-33337","firebird","buffer-overflow","denial-of-service"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eFirebird, a widely used open-source relational database management system, is susceptible to a critical buffer overflow vulnerability. Present in versions prior to 5.0.4, 4.0.7, and 3.0.14, the vulnerability resides within the \u003ccode\u003exdr_datum()\u003c/code\u003e function, responsible for deserializing slice packets. This function fails to adequately validate the length of cstring data against the slice descriptor bounds. Consequently, an attacker can craft a malicious packet containing an oversized cstring, leading to a buffer overflow. An unauthenticated attacker exploiting this vulnerability can send a crafted packet to the Firebird server, potentially causing a denial-of-service condition via a crash or, more seriously, achieving arbitrary code execution on the affected system. Organizations utilizing vulnerable Firebird versions are urged to upgrade to versions 5.0.4, 4.0.7, or 3.0.14 to mitigate this risk.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a Firebird server running a vulnerable version (prior to 5.0.4, 4.0.7, or 3.0.14).\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious slice packet designed to exploit the \u003ccode\u003exdr_datum()\u003c/code\u003e function\u0026rsquo;s insufficient bounds checking. This packet includes an overly long cstring.\u003c/li\u003e\n\u003cli\u003eThe attacker establishes a network connection to the Firebird server.\u003c/li\u003e\n\u003cli\u003eThe attacker transmits the crafted malicious slice packet to the Firebird server.\u003c/li\u003e\n\u003cli\u003eThe Firebird server\u0026rsquo;s \u003ccode\u003exdr_datum()\u003c/code\u003e function processes the malicious packet without proper cstring length validation.\u003c/li\u003e\n\u003cli\u003eThe oversized cstring overflows the allocated buffer during deserialization.\u003c/li\u003e\n\u003cli\u003eThe buffer overflow corrupts adjacent memory regions, potentially overwriting critical data structures or executable code.\u003c/li\u003e\n\u003cli\u003eDepending on the overwritten memory, the server either crashes, leading to denial of service, or the attacker achieves arbitrary code execution, enabling them to gain control of the system.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability could lead to a denial-of-service condition due to a server crash, disrupting database services and impacting applications reliant on the Firebird database. In a more severe scenario, an attacker could gain arbitrary code execution on the server, allowing them to potentially steal sensitive data, compromise the integrity of the database, or use the compromised server as a launchpad for further attacks within the network. While specific victim counts are unavailable, the widespread use of Firebird implies a significant potential impact across various sectors.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eImmediately upgrade Firebird servers to versions 5.0.4, 4.0.7, or 3.0.14 to patch CVE-2026-33337 and eliminate the buffer overflow vulnerability.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026ldquo;Detect Firebird Slice Packet Overflow Attempt\u0026rdquo; to identify potential exploitation attempts based on anomalous network traffic patterns.\u003c/li\u003e\n\u003cli\u003eMonitor network traffic for connections to Firebird servers originating from unexpected or untrusted sources to detect potential reconnaissance or exploitation attempts. Enable network connection logging to support this monitoring.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-17T19:16:36Z","date_published":"2026-04-17T19:16:36Z","id":"/briefs/2026-04-firebird-overflow/","summary":"Firebird versions before 5.0.4, 4.0.7, and 3.0.14 are vulnerable to a buffer overflow in the xdr_datum() function during slice packet deserialization, enabling unauthenticated attackers to cause a crash or potentially achieve arbitrary code execution by sending a malicious packet.","title":"Firebird Database Server Slice Packet Deserialization Buffer Overflow","url":"https://feed.craftedsignal.io/briefs/2026-04-firebird-overflow/"}],"language":"en","title":"CraftedSignal Threat Feed — Cve-2026-33337","version":"https://jsonfeed.org/version/1.1"}