CVE-2017-7302 in binutils
Summary
by MITRE
The Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.28, has a swap_std_reloc_out function in bfd/aoutx.h that is vulnerable to an invalid read (of size 4) because of missing checks for relocs that could not be recognised. 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-2017-7302 resides within the Binary File Descriptor library, commonly known as BFD or libbfd, which is a core component of GNU Binutils version 2.28. This library serves as a foundational element for various binary manipulation tools including strip, objdump, and ld. The flaw specifically manifests in the swap_std_reloc_out function located in the bfd/aoutx.h header file, which is responsible for handling relocation information during binary processing. The vulnerability represents a classic case of improper input validation where the function fails to properly verify the legitimacy of relocation entries before attempting to process them, creating a scenario where arbitrary memory access can occur.
The technical nature of this vulnerability stems from a missing validation check that should occur before the function attempts to read relocation data. When the swap_std_reloc_out function encounters a relocation entry that it cannot recognize or categorize properly, it proceeds to read memory at an invalid offset, specifically performing an invalid read of size 4 bytes. This type of memory access violation constitutes a memory safety issue that falls under the CWE-125 vulnerability category, which describes "Out-of-bounds Read" conditions. The function's failure to validate relocation entries before processing them creates a path where maliciously crafted binary files could trigger the invalid memory access, leading to unpredictable behavior including program crashes or potential exploitation.
The operational impact of this vulnerability extends beyond simple program termination, as it affects core Binutils utilities that system administrators and developers rely upon for binary file manipulation and analysis. When the strip utility encounters a binary file containing malformed relocation entries, the utility crashes due to the invalid memory read, effectively rendering the tool unusable for its intended purpose. This crash scenario represents a denial of service condition that can significantly impact development workflows, build systems, and automated security scanning processes that depend on these utilities. The vulnerability's exploitation potential increases when considering that many system tools and scripts rely on strip and similar utilities for their operations, potentially creating cascading failures throughout complex software ecosystems.
The vulnerability's relationship to established cybersecurity frameworks reveals its alignment with several ATT&CK techniques including T1059.007 for Command and Scripting Interpreter and T1489 for Service Stop, as the crash can be leveraged to disrupt normal system operations. From a defensive perspective, this vulnerability demonstrates the critical importance of input validation and proper error handling in security-critical libraries. The issue highlights the need for robust validation of binary formats and relocation entries, particularly in libraries that serve as foundational components for multiple security and development tools. Organizations should implement comprehensive patch management procedures to address this vulnerability, ensuring that all systems utilizing GNU Binutils 2.28 or earlier versions receive the necessary updates containing the fix for the missing relocation validation checks. The fix typically involves adding proper validation logic to ensure that relocation entries are recognized and valid before attempting to process their contents, thereby preventing the invalid memory read condition that leads to the crash.