Firebird - CraftedSignal Threat Feedhttps://feed.craftedsignal.io/vendors/firebird/Trending threats, MITRE ATT&CK coverage, and detection metadata. Fed continuously.Hugoenhello@craftedsignal.iohello@craftedsignal.ioMon, 29 Jan 2024 12:00:00 +0000Firebird Server Denial-of-Service via Out-of-Order Authentication Segmentshttps://feed.craftedsignal.io/briefs/2024-01-29-firebird-dos/Mon, 29 Jan 2024 12:00:00 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-01-29-firebird-dos/An unauthenticated attacker can crash Firebird database servers prior to versions 5.0.4, 4.0.7 and 3.0.14 by sending out-of-order CNCT_specific_data segments during the authentication process, leading to a denial-of-service condition.Firebird is a widely used open-source relational database management system. A vulnerability exists in versions prior to 5.0.4, 4.0.7, and 3.0.14 related to the processing of CNCT_specific_data segments during the authentication handshake. The Firebird server incorrectly assumes that these segments will arrive in strictly ascending order. An attacker who can establish a network connection to the Firebird server (knowing the IP address and port) can send crafted authentication packets with out-of-order segments. This causes the Array class's grow() method to compute a negative size, resulting in a SIGSEGV crash and subsequent denial-of-service. This vulnerability allows for easy remote exploitation without requiring any valid credentials, making patching a priority.

Attack Chain

  1. Attacker identifies a vulnerable Firebird server by scanning for the default port (3050).
  2. Attacker initiates a TCP connection to the Firebird server on port 3050.
  3. The attacker sends a CNCT_protocol message to initiate the authentication process.
  4. The attacker sends CNCT_specific_data segments within the authentication packet, intentionally sending them out of order (e.g., segment 2 before segment 1).
  5. The Firebird server receives the out-of-order CNCT_specific_data segments and attempts to process them.
  6. Within the Array class's grow() method, a negative size value is calculated due to the incorrect segment order.
  7. The grow() method attempts to allocate a negative-sized array, triggering a SIGSEGV signal.
  8. The Firebird server process crashes, resulting in a denial-of-service condition.

Impact

Successful exploitation of this vulnerability leads to a denial-of-service condition on the Firebird server. This can disrupt critical applications relying on the database, causing data unavailability and potential data loss due to unsaved transactions. The impact is significant because the vulnerability is remotely exploitable without authentication, potentially affecting any exposed Firebird instance. The number of potential victims is difficult to quantify but includes any organization running vulnerable Firebird versions.

Recommendation

  • Immediately upgrade Firebird servers to versions 5.0.4, 4.0.7, or 3.0.14 to patch CVE-2026-27890.
  • Deploy the Sigma rule Detect Firebird Authentication Attempt to detect potential exploitation attempts by monitoring network connections to port 3050.
  • Consider implementing network segmentation to limit exposure of Firebird servers to untrusted networks.
  • Implement rate limiting on connections to the Firebird server port to mitigate the impact of rapid connection attempts.
]]>highadvisorycvedosfirebirdFirebird Database Server Denial-of-Service Vulnerability (CVE-2026-28212)https://feed.craftedsignal.io/briefs/2024-01-firebird-dos/Tue, 02 Jan 2024 12:00:00 +0000hello@craftedsignal.iohttps://feed.craftedsignal.io/briefs/2024-01-firebird-dos/An unauthenticated attacker can cause a denial-of-service condition on vulnerable Firebird database servers by sending a specially crafted network packet that triggers a null pointer dereference.Firebird is an open-source relational database management system. A denial-of-service vulnerability exists in Firebird versions prior to 6.0.0, 5.0.4, 4.0.7 and 3.0.14 due to improper handling of op_slice network packets. Specifically, the server passes an unprepared structure containing a null pointer to the SDL_info() function. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted packet to the server's network port, causing a null pointer dereference and subsequent server crash. This vulnerability, identified as CVE-2026-28212, can disrupt database services, affecting applications reliant on the Firebird database. The vulnerability was patched in versions 6.0.0, 5.0.4, 4.0.7 and 3.0.14.

Attack Chain

  1. Attacker identifies a vulnerable Firebird server running a version prior to 6.0.0, 5.0.4, 4.0.7 or 3.0.14.
  2. Attacker crafts a malicious op_slice network packet specifically designed to trigger the vulnerability.
  3. Attacker establishes a network connection to the Firebird server's port (typically 3050).
  4. Attacker sends the crafted op_slice packet to the Firebird server.
  5. The server processes the malicious packet, passing an unprepared structure with a null pointer to the SDL_info() function.
  6. The SDL_info() function attempts to dereference the null pointer.
  7. A null pointer dereference occurs, leading to a server crash.
  8. The Firebird database server becomes unavailable, resulting in a denial-of-service condition.

Impact

Successful exploitation of CVE-2026-28212 results in a denial-of-service condition, rendering the Firebird database server unavailable. This can disrupt applications and services that rely on the database, leading to data unavailability and potential business interruption. While the vulnerability itself does not lead to data compromise, the loss of availability can have significant operational and financial consequences. This issue affects versions of Firebird prior to 6.0.0, 5.0.4, 4.0.7, and 3.0.14.

Recommendation

  • Upgrade Firebird database servers to version 6.0.0, 5.0.4, 4.0.7 or 3.0.14 or later to patch CVE-2026-28212.
  • Deploy the Sigma rule Detect Firebird SDL_info Null Pointer Dereference to identify potential exploitation attempts by detecting network connections followed by server crashes.
  • Monitor network traffic to Firebird servers for unusual or malformed packets using the Detect Malformed Firebird Packets Sigma rule, particularly focusing on packets directed to port 3050.
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