CVE-2018-13033 in binutils
Summary
by MITRE
The Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.30, allows remote attackers to cause a denial of service (excessive memory allocation and application crash) via a crafted ELF file, as demonstrated by _bfd_elf_parse_attributes in elf-attrs.c and bfd_malloc in libbfd.c. This can occur during execution of nm.
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Analysis
by VulDB Data Team • 03/29/2023
The vulnerability identified as CVE-2018-13033 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 fundamental interface for handling various binary file formats, including elf files, and is widely utilized by tools such as nm, objdump, and ld. The flaw manifests specifically in version 2.30 of the GNU Binutils distribution where the BFD library fails to properly validate memory allocation requests when processing specially crafted ELF files. The vulnerability affects the nm utility which is used to list symbols from object files, making it particularly concerning as nm is a frequently used tool in development and debugging workflows. The issue stems from insufficient bounds checking in the elf-attrs.c file where the _bfd_elf_parse_attributes function processes attribute information within ELF files without adequate safeguards against excessive memory consumption patterns.
The technical exploitation of this vulnerability occurs when a maliciously crafted ELF file is processed by the nm utility, triggering a memory allocation that exceeds normal operational parameters. The attack vector specifically targets the bfd_malloc function in libbfd.c which handles dynamic memory allocation requests, causing the application to allocate excessive memory resources that ultimately leads to application crash and denial of service. This occurs because the BFD library does not properly validate or limit the size of memory allocations requested during the parsing of ELF file attributes, allowing an attacker to craft a file that triggers unbounded memory growth. The vulnerability is particularly dangerous because it can be triggered through legitimate file processing operations without requiring special privileges, making it exploitable by unauthenticated remote attackers who can simply provide a malicious ELF file for processing. The flaw demonstrates characteristics consistent with CWE-772, which describes insufficient resource pool size limits, and represents a classic example of a denial of service vulnerability through resource exhaustion.
The operational impact of CVE-2018-13033 extends beyond simple service disruption as it affects the reliability and availability of critical development and system administration tools. When exploited, the vulnerability can cause the nm utility to consume excessive memory resources and crash, effectively rendering this essential tool unusable for symbol listing operations. This impacts developers, system administrators, and automated build systems that rely on nm for various tasks including library analysis, symbol resolution, and debugging operations. The vulnerability particularly affects environments where automated scanning or processing of binary files occurs, as the denial of service can be triggered without user interaction, potentially allowing attackers to disrupt continuous integration pipelines or automated security scanning processes. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 which covers network denial of service attacks, and T1588.002 which involves developing capabilities for execution of malicious code. The vulnerability's impact is amplified in enterprise environments where nm is used extensively for software analysis and security auditing operations.
Mitigation strategies for CVE-2018-13033 focus primarily on updating to patched versions of GNU Binutils where the memory allocation validation has been strengthened. The most effective solution involves upgrading to GNU Binutils 2.31 or later versions where the vulnerability has been addressed through enhanced bounds checking and memory allocation limits in the affected functions. Organizations should implement automated patch management processes to ensure all systems running nm or other tools dependent on BFD are updated promptly. Additionally, defensive measures include implementing file validation procedures that scan for suspicious ELF file characteristics before processing, and deploying monitoring systems to detect unusual memory consumption patterns during binary file processing. Network segmentation and access controls can help limit exposure by restricting access to systems where nm is executed with untrusted file inputs. Security teams should also consider implementing sandboxing techniques when processing unknown binary files, particularly in automated environments where the vulnerability could be exploited through unattended processing of potentially malicious files. The vulnerability serves as a reminder of the importance of proper input validation in security-critical libraries and highlights the need for comprehensive testing of memory allocation behaviors in binary processing utilities.