CVE-2023-39128 in gdb
Summary
by MITRE • 07/25/2023
GNU gdb (GDB) 13.0.50.20220805-git was discovered to contain a stack overflow via the function ada_decode at /gdb/ada-lang.c.
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Analysis
by VulDB Data Team • 01/23/2026
The vulnerability identified as CVE-2023-39128 represents a critical stack overflow condition within GNU GDB version 13.0.50.20220805-git, specifically manifesting in the ada_decode function located at /gdb/ada-lang.c. This issue arises from inadequate input validation and memory management practices within the debugger's Ada language support module, creating a potential pathway for arbitrary code execution or system compromise. The stack overflow occurs when processing malformed or untrusted Ada language data structures, particularly during the decoding phase of Ada language constructs. Such vulnerabilities are particularly dangerous in debugging environments where analysts often process untrusted code samples or are subjected to targeted attacks through malicious debug data. The flaw demonstrates a classic buffer overflow pattern where insufficient bounds checking allows attackers to overwrite adjacent stack memory, potentially corrupting program execution flow or injecting malicious code. This vulnerability directly relates to CWE-121 Stack-based Buffer Overflow, which is categorized under the broader weakness class of buffer overflows that occur when data is written beyond the boundaries of a fixed-length buffer on the stack. The impact of this vulnerability extends beyond simple crash conditions, as it could enable remote code execution or privilege escalation depending on the execution context and the attacker's access level. When exploited, this vulnerability allows an adversary to manipulate the program's execution flow by overwriting return addresses or other critical stack variables, potentially leading to complete system compromise. The Ada language support module in GDB is particularly sensitive to this issue since Ada programming constructs often involve complex data structures and type information that require careful parsing and decoding. This makes the vulnerability especially concerning for security researchers, developers, and system administrators who rely on GDB for debugging Ada applications or analyzing potentially malicious Ada code. The vulnerability's exploitation requires a specific scenario where the debugger processes malformed Ada language data, making it somewhat more targeted than general buffer overflow vulnerabilities, but still represents a significant security risk in debugging environments. Organizations using GDB for security analysis, penetration testing, or software development may be exposed to this risk when processing untrusted Ada code or when GDB is executed in environments where attackers could inject malicious data into the debugging process. The issue also aligns with ATT&CK technique T1059.006 Command and Scripting Interpreter: Python, as it could enable attackers to leverage debugging environments for code injection or privilege escalation. The vulnerability's presence in a widely-used debugging tool like GDB creates a substantial risk for security professionals who may inadvertently expose themselves to exploitation when debugging untrusted code. This makes the vulnerability particularly relevant in threat hunting and incident response scenarios where analysts may be processing potentially malicious code samples through debugging tools. The stack overflow in ada_decode represents a fundamental flaw in the software's defensive programming practices, where proper input validation and memory boundary checking are missing or insufficient to prevent malicious data from causing unintended program behavior. The vulnerability demonstrates the importance of robust memory safety practices in debugging tools, as these applications often operate with elevated privileges and handle complex data structures that could be manipulated to cause system compromise. Security researchers should consider this vulnerability when evaluating the security posture of debugging environments and when assessing the risks associated with using GDB for analyzing potentially malicious code. The fix for this vulnerability would typically involve implementing proper bounds checking, input sanitization, and memory allocation practices within the ada_decode function to prevent buffer overflows when processing Ada language constructs. This would align with industry best practices for secure coding and help prevent similar vulnerabilities from being introduced in future versions of the debugger. Organizations should prioritize updating to patched versions of GDB or implementing compensating controls to mitigate the risk associated with this stack overflow vulnerability in their debugging and security analysis workflows. The vulnerability also highlights the need for continuous security testing of development and debugging tools, as these applications often become targets for exploitation due to their privileged execution contexts and complex processing requirements.