CVE-2017-17121 in binutils
Summary
by MITRE
The Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.29.1, allows remote attackers to cause a denial of service (memory access violation) or possibly have unspecified other impact via a COFF binary in which a relocation refers to a location after the end of the to-be-relocated section.
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Analysis
by VulDB Data Team • 01/16/2023
The vulnerability identified as CVE-2017-17121 resides within the Binary File Descriptor library, commonly known as BFD or libbfd, which is a core component of GNU Binutils version 2.29.1. This library serves as a fundamental interface for handling various binary file formats, including object files, archives, and executable binaries across different architectures. The flaw manifests when processing COFF (Common Object File Format) binaries that contain malformed relocation entries pointing beyond the boundaries of the section being relocated. Such malformed entries can occur due to corrupted or maliciously crafted binaries that exploit the library's insufficient bounds checking mechanisms.
The technical implementation of this vulnerability stems from inadequate validation of relocation entries within COFF binary files. When the BFD library attempts to process a relocation entry that references a memory location beyond the actual end of the section data, it triggers an access violation during memory operations. This condition occurs because the library fails to verify that relocation targets fall within the valid bounds of the section being processed. The flaw represents a classic buffer over-read scenario where the library attempts to access memory beyond allocated boundaries, leading to unpredictable behavior that can manifest as program crashes or memory corruption.
From an operational perspective, this vulnerability presents significant risks for systems that process untrusted binary files through the BFD library. Attackers could potentially exploit this weakness to cause denial of service conditions by crafting malicious COFF binaries that trigger memory access violations in applications relying on BFD for binary analysis. The impact extends beyond simple service disruption, as the unspecified other impacts mentioned in the CVE description suggest potential for more severe consequences including information disclosure or privilege escalation depending on the execution context. Systems utilizing tools like objdump, nm, or other utilities built upon BFD are particularly vulnerable since these applications frequently process binary files from untrusted sources.
The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software implementations, and can be categorized under ATT&CK technique T1059 for execution through command-line interfaces. Organizations should implement immediate mitigations including updating to patched versions of GNU Binutils where the vulnerability has been addressed through proper bounds checking and validation of relocation entries. Additionally, deploying input validation controls and restricting processing of untrusted binary files can help reduce exposure. System administrators should prioritize patching affected systems, particularly those running older versions of GNU Binutils that may be vulnerable to this class of memory access violations. The remediation process should include comprehensive testing of updated libraries to ensure that legitimate binary processing functionality remains intact while eliminating the potential for exploitation through malformed COFF relocation entries.