CVE-2003-0102 in NetBSD
Summary
by MITRE
Buffer overflow in tryelf() in readelf.c of the file command allows attackers to execute arbitrary code as the user running file, possibly via a large entity size value in an ELF header (elfhdr.e_shentsize).
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Analysis
by VulDB Data Team • 01/23/2025
The vulnerability described in CVE-2003-0102 represents a critical buffer overflow flaw within the file command's implementation of the readelf.c module. This security issue specifically targets the tryelf() function which processes ELF (Executable and Linkable Format) headers to determine file types. The flaw occurs when the application encounters an excessively large entity size value within the ELF header structure, particularly in the elfhdr.e_shentsize field which defines the size of section header entries. This buffer overflow condition arises from inadequate input validation and bounds checking within the file command's ELF parsing logic, creating a potential pathway for privilege escalation attacks.
The technical implementation of this vulnerability stems from improper handling of user-supplied data within the ELF header structure. When the file command processes a maliciously crafted ELF file, the e_shentsize field contains a value that exceeds the allocated buffer space intended for storing section header information. This condition allows attackers to overwrite adjacent memory locations, potentially corrupting the program's execution flow and enabling arbitrary code execution. The vulnerability specifically affects systems where the file command is executed with elevated privileges, as the attacker can leverage this flaw to execute malicious code with the same permissions as the running process. The attack vector is particularly insidious because it requires no special privileges to craft the malicious input, making it accessible to any potential attacker who can convince a user to process a specially crafted file.
The operational impact of this vulnerability extends beyond simple code execution, potentially allowing for complete system compromise when the file command is used in automated environments or with elevated privileges. The vulnerability affects systems where the file command is widely used for file type detection, including web servers, automated build systems, and network scanning tools that rely on this utility. When exploited, the buffer overflow can lead to denial of service conditions, unauthorized privilege escalation, and complete system compromise depending on the execution context. The vulnerability is particularly concerning in environments where untrusted files are processed automatically, as it provides a direct path for remote code execution without requiring user interaction beyond the initial file processing.
Mitigation strategies for CVE-2003-0102 should focus on immediate patching of affected systems and implementation of input validation controls. The primary remediation involves updating the file command to a patched version that properly validates ELF header values and implements robust bounds checking mechanisms. Organizations should also implement defensive programming practices such as using safe string handling functions and implementing stack canaries to detect buffer overflow conditions. Additionally, system administrators should consider restricting execution privileges for the file command, particularly in automated processing environments, and implement file type validation at network boundaries to prevent malicious files from reaching systems that process them. This vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation that enables privilege escalation attacks. The ATT&CK framework categorizes this as a privilege escalation technique through software exploitation, specifically targeting command execution capabilities within operating systems.