CVE-2003-0853 in fileutils
Summary
by MITRE
An integer overflow in ls in the fileutils or coreutils packages may allow local users to cause a denial of service or execute arbitrary code via a large -w value, which could be remotely exploited via applications that use ls, such as wu-ftpd.
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Analysis
by VulDB Data Team • 09/28/2024
The vulnerability identified as CVE-2003-0853 represents a critical integer overflow flaw within the ls command utility that is part of the coreutils package ecosystem. This vulnerability stems from improper input validation when processing the -w parameter, which controls the number of columns for output formatting. The flaw exists in the coreutils implementation where the ls utility fails to properly handle excessively large integer values passed through the -w flag, creating a scenario where arithmetic operations exceed the maximum representable value for signed integers.
The technical exploitation of this vulnerability occurs when a local attacker provides an extremely large value to the -w parameter, typically in the range of maximum integer limits or beyond. When the ls command processes this input, the integer overflow causes the program to behave unpredictably, potentially leading to memory corruption that can be leveraged for arbitrary code execution. The overflow condition manifests when the program attempts to perform calculations involving the provided width value, resulting in wraparound behavior where large positive values become negative or zero, disrupting the normal execution flow.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to encompass potential privilege escalation and remote code execution capabilities. The vulnerability can be remotely exploited through applications that invoke ls with user-supplied parameters, such as the wu-ftpd FTP server implementation mentioned in the original description. When such applications process user input through ls commands, malicious users can craft inputs that trigger the integer overflow condition, potentially allowing them to execute arbitrary code with the privileges of the process running ls. This creates a significant security risk in environments where FTP servers or similar applications rely on ls functionality for directory listing operations.
The vulnerability maps to CWE-190, which specifically addresses integer overflow conditions, and aligns with ATT&CK technique T1059.007 for command and script injection. This mapping reflects the fundamental nature of the flaw as a programming error that allows attackers to manipulate integer values to achieve unintended program behavior. The vulnerability also demonstrates characteristics of T1210, which involves exploitation of vulnerabilities in remote services through input validation failures, particularly when applications fail to properly sanitize user inputs before processing them through system utilities.
Mitigation strategies for this vulnerability require immediate patching of affected coreutils installations, as the flaw exists in the fundamental system utility implementation. System administrators should ensure all systems running affected versions of coreutils are updated to patched releases that properly validate integer inputs and prevent overflow conditions. Additionally, implementing input validation controls at the application level where ls commands are invoked can provide additional defense in depth. Network segmentation and access controls should be implemented to limit exposure of vulnerable services, while monitoring systems should be configured to detect unusual ls command usage patterns that might indicate exploitation attempts. The vulnerability highlights the importance of proper integer handling and input validation in system utilities, particularly those that process user-supplied data in multi-user environments where privilege escalation risks are significant.