CVE-2017-7304 in binutils
Summary
by MITRE
The Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.28, is vulnerable to an invalid read (of size 8) because of missing a check (in the copy_special_section_fields function) for an invalid sh_link field before attempting to follow it. This vulnerability causes Binutils utilities like strip to crash.
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Analysis
by VulDB Data Team • 12/04/2024
The vulnerability identified as CVE-2017-7304 resides within the Binary File Descriptor library, commonly known as BFD or libbfd, which is a core component of the GNU Binutils suite. This library serves as a universal interface for reading and writing binary object files across various formats, making it a critical element in the toolchain used for software development, debugging, and system administration. The specific flaw manifests in version 2.28 of GNU Binutils, where the copy_special_section_fields function fails to validate the sh_link field before attempting to dereference it. This oversight creates a scenario where an attacker can craft malicious binary files that trigger an invalid memory read operation of 8 bytes in size.
The technical nature of this vulnerability stems from a classic lack of input validation within the BFD library's section field processing mechanism. The sh_link field in ELF (Executable and Linkable Format) files serves as a pointer to another section within the same file, typically used for linking symbol tables with their corresponding string tables. When this field contains an invalid value or points to an out-of-bounds memory location, the copy_special_section_fields function proceeds without proper bounds checking, leading to memory access violations. This type of vulnerability falls under CWE-125, which describes "Out-of-bounds Read" conditions where programs access memory beyond the intended boundaries, and more specifically aligns with CWE-704, which covers "Incorrect Type Conversion or Cast" when dealing with section link fields.
The operational impact of this vulnerability extends beyond simple program crashes, as it affects critical Binutils utilities such as strip, which is commonly used to remove unnecessary sections from executable files to reduce their size. When an attacker can successfully trigger this vulnerability through malformed input files, they can cause the strip utility to crash, potentially leading to denial of service conditions in automated build systems or development environments. This vulnerability is particularly concerning in environments where automated processing of binary files occurs, as it could be exploited to disrupt legitimate compilation and linking processes, creating cascading failures in software development workflows. The ATT&CK framework categorizes this type of vulnerability under T1499.004, "Endpoint Denial of Service," where adversaries leverage software weaknesses to cause system disruption, and T1059.007, "Command and Scripting Interpreter: Unix Shell," when exploited through shell-based automated build processes.
Mitigation strategies for CVE-2017-7304 involve immediate patching of affected GNU Binutils installations to version 2.29 or later, where the missing validation check has been implemented in the copy_special_section_fields function. System administrators should also implement proper input sanitization measures when processing binary files, particularly in environments where untrusted files are handled. The vulnerability highlights the importance of robust input validation in low-level system libraries that handle file format parsing, as these components often operate with elevated privileges and can affect the entire system if exploited. Additionally, organizations should consider implementing file format validation checks and sandboxing mechanisms for automated processing of binary content to prevent exploitation of similar vulnerabilities in other parts of the system.