CVE-2018-6323 in binutils
Summary
by MITRE
The elf_object_p function in elfcode.h in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.29.1, has an unsigned integer overflow because bfd_size_type multiplication is not used. A crafted ELF file allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact.
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Analysis
by VulDB Data Team • 09/04/2025
The vulnerability identified as CVE-2018-6323 resides within the Binary File Descriptor (BFD) library, specifically in the elf_object_p function located in elfcode.h. This library component is part of GNU Binutils 2.29.1 and serves as a fundamental tool for handling various binary file formats including ELF files. The flaw manifests as an unsigned integer overflow that occurs when performing size calculations without proper use of bfd_size_type multiplication. This particular vulnerability affects the core functionality of BFD when processing ELF files, making it a critical concern for systems that rely on this library for binary analysis and manipulation. The issue enables remote attackers to exploit the system through specially crafted ELF files, potentially leading to system instability or more severe consequences.
The technical implementation of this vulnerability stems from improper handling of size calculations within the elf_object_p function. When processing ELF files, the function performs arithmetic operations that should use bfd_size_type to prevent overflow conditions, but instead relies on standard unsigned integer operations. This oversight creates a scenario where an attacker can craft an ELF file with malicious size parameters that, when processed by the BFD library, trigger an integer overflow. The overflow occurs because the multiplication of size values does not account for the possibility of exceeding the maximum value that can be represented by an unsigned integer type, leading to unexpected behavior in the memory allocation and processing routines. This type of vulnerability is categorized as CWE-190, which specifically addresses integer overflow conditions that can result in memory corruption or other security issues.
The operational impact of CVE-2018-6323 extends beyond simple denial of service scenarios, though DoS remains a primary concern. When exploited, the vulnerability can cause application crashes that disrupt legitimate system operations, particularly affecting tools that depend on BFD for processing binary files such as objdump, nm, and readelf. The potential for unspecified other impacts suggests that the integer overflow might be exploitable for more sophisticated attacks including memory corruption that could potentially enable code execution or privilege escalation. Systems that automatically process or analyze ELF files from untrusted sources are particularly vulnerable, including security scanning tools, malware analysis frameworks, and automated build systems that might encounter maliciously crafted binary files during normal operations.
Mitigation strategies for CVE-2018-6323 should focus on both immediate patching and operational security measures. The most effective solution involves upgrading to GNU Binutils version 2.30 or later, where the integer overflow issue has been resolved through proper use of bfd_size_type multiplication in the affected function. Organizations should prioritize patching systems running vulnerable versions of Binutils, particularly those that process binary files from external sources or untrusted environments. Additionally, implementing defensive programming practices such as input validation and size checking for ELF files can provide additional protection layers. Security teams should also consider deploying network monitoring solutions to detect attempts to exploit this vulnerability through crafted ELF files, while following ATT&CK framework techniques for detecting malicious binary file processing activities. Organizations using older versions of Binutils should implement strict file validation procedures and avoid automatic processing of binary files from untrusted sources until proper patches are applied.