CVE-2019-7560 in Boolector
Summary
by MITRE
In parser/btorsmt2.c in Boolector 3.0.0, opening a specially crafted input file leads to a use after free in get_failed_assumptions or btor_delete.
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Analysis
by VulDB Data Team • 07/06/2023
The vulnerability identified as CVE-2019-7560 resides within the Boolector 3.0.0 symbolic execution engine, specifically in the btorsmt2.c parser component responsible for processing SMT2 formatted input files. This flaw represents a critical memory safety issue that can be exploited through manipulation of input file structures, potentially leading to arbitrary code execution or system compromise. The vulnerability manifests when the parser encounters a specially crafted input file that triggers improper memory management during the parsing process.
The technical root cause of this vulnerability stems from a use-after-free condition occurring in the get_failed_assumptions or btor_delete functions within the parser module. This memory safety flaw arises from the improper handling of dynamically allocated memory blocks that are freed but subsequently accessed by the parser logic. The vulnerability is classified under CWE-416 as a use-after-free error, which occurs when a program continues to reference memory after it has been freed, creating potential exploitation opportunities for attackers who can control the input stream. The specific function calls involved in the exploit chain demonstrate how the parser's internal state management fails to properly track memory allocation and deallocation cycles during input processing.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can be leveraged to achieve arbitrary code execution on systems running vulnerable versions of Boolector. Attackers who can influence input to the parser can craft malicious files that trigger the use-after-free condition, potentially allowing them to execute code with the privileges of the affected process. This poses significant risks in environments where Boolector is used for security analysis, formal verification, or automated testing, as adversaries could exploit this weakness to compromise the integrity of verification processes or gain unauthorized access to systems. The vulnerability's exploitation requires careful crafting of input files to manipulate the parser's internal state machine, making it particularly dangerous in automated environments where input validation may be insufficient.
Mitigation strategies for CVE-2019-7560 should prioritize immediate patching of Boolector installations to versions that address the memory management issues in the btorsmt2.c parser. Organizations should implement strict input validation procedures and sandboxing mechanisms when processing untrusted SMT2 files, as recommended by the ATT&CK framework's defensive techniques for memory corruption vulnerabilities. System administrators should also consider implementing network segmentation and access controls to limit exposure to potentially malicious input files. Additionally, regular security audits of symbolic execution tools and formal verification engines should be conducted to identify similar memory safety issues that may exist in other components of the software ecosystem. The vulnerability highlights the importance of rigorous memory management practices in security-critical software and demonstrates how seemingly isolated parser issues can have far-reaching consequences in automated security tools.