CVE-2012-2090 in SimGear
Summary
by MITRE
Multiple format string vulnerabilities in FlightGear 2.6 and earlier and SimGear 2.6 and earlier allow user-assisted remote attackers to cause a denial of service and possibly execute arbitrary code via format string specifiers in certain data chunk values in an aircraft xml model to (1) fgfs/flightgear/src/Cockpit/panel.cxx or (2) fgfs/flightgear/src/Network/generic.cxx, or (3) a scene graph model to simgear/simgear/scene/model/SGText.cxx.
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Analysis
by VulDB Data Team • 12/04/2021
The vulnerability identified as CVE-2012-2090 represents a critical format string vulnerability affecting FlightGear flight simulation software and its underlying SimGear library. This issue impacts versions 2.6 and earlier of both components, creating a significant security risk for users who engage with aircraft model files. The vulnerability stems from inadequate input validation within the parsing of xml model data, specifically when processing data chunk values that contain format string specifiers. These specifiers are typically used in programming languages like C to control output formatting but become dangerous when user-controlled input is processed without proper sanitization. The flaw exists in three primary locations within the software architecture, each representing a distinct entry point for exploitation.
The technical implementation of this vulnerability occurs when the flightgear application processes aircraft model files containing specially crafted xml data structures. In the cockpit panel component located at fgfs/flightgear/src/Cockpit/panel.cxx, the application fails to properly validate format string parameters during xml parsing operations. Similarly, the generic network component at fgfs/flightgear/src/Network/generic.cxx and the scene graph text rendering component at simgear/simgear/scene/model/SGText.cxx exhibit the same vulnerability. When these components encounter maliciously constructed format specifiers within xml model files, they execute the specified formatting operations without proper input sanitization. This creates an environment where attackers can manipulate memory locations through format string exploitation techniques, potentially leading to stack corruption, memory disclosure, or code execution. The vulnerability aligns with CWE-134, which specifically addresses format string vulnerabilities where format strings are constructed from user-controlled data.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution capabilities. An attacker who can convince a victim to load a malicious aircraft model file could trigger a crash or more severely, execute arbitrary code with the privileges of the running application. This represents a significant risk in environments where flight simulation software is used for training or development purposes, particularly when users might encounter untrusted aircraft models from online repositories or community downloads. The vulnerability affects both the flightgear client application and the underlying simgear library, meaning that any software component relying on these libraries could be impacted. The attack vector requires user assistance, typically through social engineering to convince victims to load malicious models, but once triggered, the exploitation can occur automatically during normal operation. This vulnerability demonstrates the importance of input validation in security-critical applications, particularly those that process user-supplied data structures.
Mitigation strategies for CVE-2012-2090 focus on immediate software updates and input validation improvements. The most effective solution involves upgrading to FlightGear versions 2.8 and later, where the format string vulnerabilities have been addressed through proper input sanitization and validation mechanisms. System administrators should implement strict content filtering policies for aircraft model files, particularly when these come from untrusted sources. The implementation of proper input validation in xml parsing components should enforce strict schema validation and reject any data containing potentially dangerous format string sequences. Additionally, users should be educated about the risks of loading aircraft models from unknown sources and the importance of verifying model integrity before loading. Security monitoring should include detection of unusual memory access patterns that might indicate format string exploitation attempts. Organizations using flightgear in training environments should establish secure software update procedures and maintain inventory of all aircraft models in their libraries. This vulnerability highlights the need for comprehensive security testing of parsing components and adherence to secure coding practices that prevent format string vulnerabilities. The attack patterns associated with this vulnerability align with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation may involve manipulation of execution environments through crafted input data.