CVE-2019-7559 in Btor2Tools
Summary
by MITRE
In btor2parser/btor2parser.c in Boolector Btor2Tools before 2019-01-15, opening a specially crafted input file leads to an out of bounds write in pusht_bfr.
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Analysis
by VulDB Data Team • 07/06/2023
The vulnerability identified as CVE-2019-7559 resides within the btor2parser component of Boolector Btor2Tools, a formal verification tool used for solving satisfiability problems in software and hardware systems. This issue affects versions prior to the 2019-01-15 release, indicating a specific timeframe where the software contained a critical flaw that could be exploited by attackers. The vulnerability manifests when the parser encounters a specially crafted input file that triggers an out of bounds write condition in the pusht_bfr function, which operates within the broader context of Boolean satisfiability solving and formal verification processes.
The technical flaw represents a classic buffer overflow vulnerability that occurs during the parsing of input files, specifically within the pushback buffer management mechanism. When the btor2parser processes malformed input data, it fails to properly validate array bounds before writing data to memory locations, resulting in an out of bounds write that can overwrite adjacent memory regions. This type of vulnerability falls under CWE-787, which specifically addresses out-of-bounds write conditions that can lead to arbitrary code execution or system instability. The pusht_bfr function, responsible for managing pushback buffers during parsing operations, becomes the focal point of this memory corruption issue, where insufficient bounds checking allows attackers to manipulate memory layout and potentially execute malicious code.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides a potential pathway for remote code execution within systems that utilize Boolector Btor2Tools for formal verification tasks. Attackers could craft malicious input files that, when processed by vulnerable versions of the tool, would trigger the out of bounds write condition and potentially allow them to execute arbitrary code on systems running the affected software. This poses significant risks in environments where formal verification tools are used for security-critical applications, as the compromise of such tools could undermine the integrity of security analysis processes. The vulnerability is particularly concerning in automated verification pipelines where input files might be sourced from untrusted parties, as it could be exploited to gain unauthorized access to verification environments.
Mitigation strategies for CVE-2019-7559 primarily focus on updating to the patched version of Boolector Btor2Tools released on or after January 15, 2019, which contains proper bounds checking mechanisms to prevent the out of bounds write condition. Organizations should also implement input validation procedures that sanitize all files processed by the tool, including implementing file format restrictions and performing preliminary analysis of input data before processing. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1059, where adversaries may attempt to execute malicious code through legitimate system tools, and T1203, which involves the exploitation of software vulnerabilities for privilege escalation. System administrators should also consider implementing monitoring solutions that detect anomalous memory access patterns and unusual behavior in verification environments to identify potential exploitation attempts. Additionally, the vulnerability demonstrates the importance of proper memory management practices and input validation in security-critical software, reinforcing the need for comprehensive security testing and code review processes that can identify such flaws before they can be exploited in real-world scenarios.