CVE-2017-14932 in binutils
Summary
by MITRE
decode_line_info in dwarf2.c in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.29, allows remote attackers to cause a denial of service (infinite loop) via a crafted ELF file.
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Analysis
by VulDB Data Team • 12/30/2022
The vulnerability identified as CVE-2017-14932 represents a critical denial of service flaw within the Binary File Descriptor (BFD) library component of GNU Binutils version 2.29. This issue specifically affects the decode_line_info function located in the dwarf2.c file, which serves as a core component for processing debugging information within binary files. The BFD library acts as a universal interface for reading and writing various binary file formats, making it a fundamental element in numerous development and security tools including gdb, objdump, and other utilities that depend on proper binary analysis capabilities. The flaw manifests when the library processes malformed ELF files that contain crafted debugging information, leading to an infinite loop condition that consumes system resources and ultimately renders the affected applications unavailable to legitimate users.
The technical nature of this vulnerability stems from insufficient input validation within the dwarf2.c implementation, particularly in how it handles line number information within DWARF debugging formats. When processing a specially crafted ELF file containing malformed line information entries, the decode_line_info function enters an iterative processing loop that fails to properly terminate due to missing boundary checks or malformed data handling. This condition creates a deterministic infinite loop where the processing routine continuously cycles through the same set of operations without making meaningful progress toward completing the parsing task. The vulnerability is classified under CWE-835, which specifically addresses the issue of infinite loops in software implementations, and represents a classic example of how improper input validation can lead to resource exhaustion and service disruption. The flaw affects the broader ATT&CK matrix entry for privilege escalation through resource exhaustion, where attackers can leverage such vulnerabilities to deny service to legitimate users.
The operational impact of CVE-2017-14932 extends beyond simple application crashes, as it can be exploited remotely through various attack vectors including file uploads, network-based binary processing, or automated analysis systems that consume user-provided binaries. Systems that rely on BFD library functions for binary analysis, such as security scanners, malware analysis frameworks, and development environments, become vulnerable to this attack. The infinite loop condition causes substantial CPU resource consumption and can potentially lead to system instability when multiple instances of the vulnerable code are triggered simultaneously. Attackers can exploit this vulnerability by preparing a malicious ELF file that contains carefully constructed debugging information, then delivering it to systems that process such files through tools utilizing the BFD library. This makes the vulnerability particularly dangerous in automated environments where binary analysis occurs without human intervention, as the denial of service can occur silently and without detection until system performance degrades significantly.
Mitigation strategies for CVE-2017-14932 primarily involve upgrading to GNU Binutils version 2.30 or later, where the vulnerability has been addressed through enhanced input validation and proper loop termination conditions in the decode_line_info function. Organizations should prioritize updating their systems that utilize BFD-dependent tools, particularly those involved in security analysis, binary processing, or automated code review systems. Additionally, implementing proper input sanitization at the application level can provide defense-in-depth measures, though the primary fix must occur at the library level. System administrators should monitor for any instances where vulnerable tools are processing untrusted binary content and consider implementing file type validation or sandboxing mechanisms to prevent exploitation. The vulnerability highlights the importance of maintaining up-to-date security toolchains and demonstrates how seemingly minor flaws in core libraries can have widespread implications across the software ecosystem, emphasizing the need for continuous security auditing and patch management processes.