CVE-2018-14038 in binutils
Summary
by MITRE
The aout_32_swap_std_reloc_out function in aoutx.h in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils before 2.31, allows remote attackers to cause a denial of service (segmentation fault and application crash) via a crafted file, as demonstrated by objcopy.
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Analysis
by VulDB Data Team • 07/29/2023
The vulnerability identified as CVE-2018-14038 resides within the Binary File Descriptor (BFD) library, specifically in the aout_32_swap_std_reloc_out function located in aoutx.h. This library component is part of GNU Binutils, a collection of essential tools for handling binary files in Unix-like systems. The flaw manifests when processing specially crafted binary files through the objcopy utility, which is commonly used for copying and converting object files between different formats. The vulnerability represents a classic buffer over-read condition that occurs during the relocation processing of aout format files, making it particularly dangerous in environments where binary file manipulation is routine.
The technical implementation of this vulnerability involves improper bounds checking within the aout_32_swap_std_reloc_out function, which handles the conversion of relocation information for 32-bit a.out format files. When a maliciously crafted file is processed by objcopy, the function attempts to access memory locations beyond the allocated buffer boundaries, leading to a segmentation fault. This occurs because the code does not adequately validate the size or structure of relocation entries before attempting to process them, allowing an attacker to manipulate the input data in such a way that it triggers memory access violations. The vulnerability is particularly insidious because it can be exploited remotely through the processing of untrusted binary files, making it a significant concern for systems that handle file conversions or perform automated binary analysis.
The operational impact of CVE-2018-14038 extends beyond simple denial of service, as it can disrupt critical system operations and potentially enable more sophisticated attacks. When the segmentation fault occurs, applications using the affected BFD library crash, which can lead to complete service disruption in environments where binary file processing is automated or continuous. This vulnerability affects systems running GNU Binutils versions prior to 2.31, making it relevant to a wide range of Unix and Linux systems that rely on these tools for software development, system administration, and security analysis. The remote exploitation capability means that attackers can trigger the vulnerability through network-based file transfers or web-based file processing, amplifying the potential impact in networked environments.
Mitigation strategies for this vulnerability primarily focus on updating to patched versions of GNU Binutils where version 2.31 or later is installed. System administrators should prioritize patching affected systems and implementing proper file validation procedures before processing untrusted binary content. The vulnerability aligns with CWE-129, which describes improper validation of length of input buffers, and relates to ATT&CK technique T1059.007 for execution through object code injection. Organizations should also consider implementing network segmentation and access controls to limit exposure to potentially malicious file processing operations, while monitoring for unusual patterns in binary file handling activities. Additionally, automated security scanning tools should be configured to detect and prevent processing of suspicious binary files that might contain the crafted input patterns designed to trigger this vulnerability.