CVE-2017-7301 in binutils
Summary
by MITRE
The Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.28, has an aout_link_add_symbols function in bfd/aoutx.h that has an off-by-one vulnerability because it does not carefully check the string offset. The vulnerability could lead to a GNU linker (ld) program crash.
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Analysis
by VulDB Data Team • 12/04/2024
The vulnerability identified as CVE-2017-7301 resides within the Binary File Descriptor library commonly known as BFD, which is a core component of the GNU Binutils suite. This library serves as a crucial interface for handling various binary file formats including object files, executables, and libraries. The specific flaw manifests in the aout_link_add_symbols function located in the bfd/aoutx.h header file, which is part of the GNU linker ld functionality. This vulnerability represents a classic off-by-one error that occurs when processing string offsets during the symbol linking process. The issue arises because the function fails to properly validate or verify the boundaries of string offsets, creating a scenario where memory access occurs beyond intended limits. Such memory corruption vulnerabilities are particularly dangerous as they can potentially be exploited to cause program crashes or, in more sophisticated scenarios, lead to arbitrary code execution.
The technical nature of this vulnerability places it squarely within the realm of memory safety issues, specifically categorized under CWE-129 Input Validation and CWE-121 Heap-based Buffer Overflow. The flaw occurs during the linking phase when the GNU linker processes binary files and attempts to resolve symbols across different object modules. When the aout_link_add_symbols function encounters malformed or specially crafted input data, it fails to properly validate the string offset calculations, leading to a situation where one additional byte is accessed beyond the allocated memory boundaries. This off-by-one error in string offset handling creates a predictable pattern of memory corruption that can manifest as a segmentation fault or more severe system instability. The vulnerability is particularly concerning because it affects the GNU linker itself, which is a fundamental tool in the compilation and linking process of software development environments.
The operational impact of CVE-2017-7301 extends beyond simple program crashes to potentially compromise entire software build environments and development workflows. When exploited, this vulnerability can cause the GNU linker to terminate abruptly during compilation processes, leading to build failures and development interruptions. In environments where automated build systems rely heavily on the GNU toolchain, such a crash could result in cascading failures across multiple projects and dependencies. The vulnerability affects GNU Binutils version 2.28 specifically, making it relevant to systems that have not yet been updated to patched versions. From an attack perspective, this vulnerability aligns with ATT&CK technique T1059 Command and Scripting Interpreter, as it can be leveraged to disrupt legitimate build processes or potentially provide a foothold for more sophisticated attacks against development infrastructure. The reliability of the GNU linker becomes compromised, affecting the integrity of software compilation processes that depend on this foundational tool.
Mitigation strategies for CVE-2017-7301 primarily focus on updating to patched versions of GNU Binutils where the vulnerability has been resolved through proper input validation and boundary checking. System administrators and developers should prioritize upgrading to GNU Binutils 2.29 or later versions that contain the necessary fixes for this off-by-one error. Additionally, implementing input validation measures at the build system level can help detect malformed binary inputs that might trigger this vulnerability. Security monitoring should include detection of unusual linker behavior or crash patterns that could indicate exploitation attempts. The fix implemented in the patched versions typically involves adding proper boundary checks to validate string offset calculations before any memory access occurs, preventing the off-by-one condition from manifesting. Organizations should also consider implementing sandboxing or containerization techniques for build environments to limit the potential impact if such vulnerabilities are exploited in development systems. Regular security assessments of development toolchains are essential to identify and remediate similar vulnerabilities before they can be exploited in production environments.