CVE-2005-4807 in Binutils
Summary
by MITRE
Stack-based buffer overflow in the as_bad function in messages.c in the GNU as (gas) assembler in Free Software Foundation GNU Binutils before 20050721 allows attackers to execute arbitrary code via a .c file with crafted inline assembly code.
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Analysis
by VulDB Data Team • 01/02/2025
The vulnerability identified as CVE-2005-4807 represents a critical stack-based buffer overflow flaw within the GNU as (gas) assembler component of the Free Software Foundation GNU Binutils suite. This vulnerability specifically affects the as_bad function located in the messages.c file, which serves as a core error reporting mechanism within the assembler. The flaw arises when processing .c source files containing crafted inline assembly code that triggers improper buffer handling during error message generation. The vulnerability was present in GNU Binutils versions prior to the 20050721 release, making it a significant security concern for systems utilizing older versions of this essential toolchain component. The issue stems from inadequate input validation and buffer size checking mechanisms that fail to properly constrain the length of error messages generated during assembly processing.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious inline assembly code within a C source file that, when processed by the vulnerable GNU as assembler, causes the as_bad function to write data beyond the bounds of a statically allocated stack buffer. This buffer overflow condition enables attackers to overwrite adjacent stack memory locations, potentially including return addresses and function pointers, which can be manipulated to redirect program execution flow. The vulnerability is particularly dangerous because it operates within the assembler context, meaning that any compilation process involving malicious inline assembly code could trigger the overflow. The flaw aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack-allocated memory regions, and demonstrates how improper memory management in error handling routines can create exploitable conditions. This type of vulnerability is categorized under ATT&CK technique T1059.008 for Execution through Command Injection, as the overflow can be leveraged to execute arbitrary code with the privileges of the assembler process.
The operational impact of CVE-2005-4807 extends beyond simple code execution, as it represents a potential pathway for privilege escalation attacks within development environments and build systems. When systems compile source code containing malicious inline assembly, the vulnerability can be exploited to gain unauthorized code execution capabilities, potentially leading to complete system compromise if the assembler runs with elevated privileges. The vulnerability affects not only individual developers but also continuous integration systems, build servers, and automated compilation environments where untrusted code may be processed. Attackers could leverage this vulnerability to introduce backdoors into software builds, modify compiled binaries, or establish persistent access points within development infrastructure. The impact is particularly severe in environments where code quality assurance processes do not properly validate source code inputs before compilation, as the vulnerability can be triggered through seemingly legitimate compilation activities. Organizations relying on GNU Binutils for software development and build processes would be at risk, especially those using older versions that have not received the security patch released in July 2005.
Mitigation strategies for CVE-2005-4807 center on immediate version updates to GNU Binutils 2.16 or later, which contain the necessary patches to address the buffer overflow condition in the as_bad function. System administrators should conduct comprehensive inventory assessments to identify all systems running vulnerable versions of GNU Binutils and prioritize patch deployment across development, testing, and production environments. Additionally, organizations should implement input validation measures that prevent untrusted code from being processed through the assembler, including code review procedures and static analysis tools that can detect potentially malicious inline assembly constructs. Security monitoring should be enhanced to detect unusual compilation activities or attempts to exploit the vulnerability through crafted source files. The vulnerability highlights the importance of maintaining up-to-date toolchain components and demonstrates how seemingly benign error handling functions can become attack vectors. Organizations should also consider implementing sandboxing or containerization strategies for compilation processes to limit the potential impact of successful exploitation attempts, as the vulnerability could be exploited in build automation systems where the assembler may have elevated system privileges. Regular security assessments of development toolchains should be conducted to identify and remediate similar vulnerabilities in other components of the software development lifecycle.