CVE-2003-0584 in BRU
Summary
by MITRE
Format string vulnerability in Backup and Restore Utility for Unix (BRU) 17.0 and earlier, when running setuid, allows local users to execute arbitrary code via format string specifiers in a command line argument.
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Analysis
by VulDB Data Team • 01/24/2025
The vulnerability described in CVE-2003-0584 represents a critical format string flaw within the Backup and Restore Utility for Unix (BRU) version 17.0 and earlier implementations. This issue specifically manifests when the utility operates with elevated privileges through setuid execution, creating a dangerous attack surface that can be exploited by local malicious actors. The BRU utility, designed for system backup and restoration operations, becomes a potential vector for privilege escalation when improperly handling user-supplied input during command line argument processing.
The technical flaw stems from the improper use of format string functions within the BRU utility's codebase, where user-provided command line arguments are directly passed to functions such as printf or sprintf without proper validation or sanitization. When these functions encounter format specifiers within user input, they interpret them as instructions for accessing memory locations and retrieving data from the stack, potentially leading to information disclosure, application crashes, or more severe exploitation opportunities. This vulnerability falls under the Common Weakness Enumeration category CWE-134, which specifically addresses the weakness of using user-controlled format strings in functions that interpret format strings, making it a well-documented and dangerous class of vulnerability.
The operational impact of this vulnerability is significant for systems running affected versions of BRU, as local users who can execute the utility with setuid privileges can leverage this flaw to execute arbitrary code with elevated system permissions. Attackers can craft malicious command line arguments containing format specifiers that manipulate the program's execution flow, potentially allowing them to overwrite critical memory locations, inject malicious code, or bypass security controls. The vulnerability essentially transforms a legitimate system utility into a privilege escalation mechanism, enabling attackers to gain root access or other elevated privileges depending on the specific implementation details and system configuration. This type of vulnerability is particularly concerning in enterprise environments where backup utilities often run with high privileges to perform their functions.
Mitigation strategies for CVE-2003-0584 should focus on immediate patching of the BRU utility to version 17.1 or later, which contains the necessary fixes to properly handle format string arguments. Organizations should also implement input validation measures that sanitize all user-supplied command line arguments before they are processed by format string functions. The principle of least privilege should be enforced by ensuring that backup utilities run with minimal required permissions rather than setuid root, and alternative backup solutions that do not exhibit similar vulnerabilities should be considered. Additionally, system administrators should monitor for any exploitation attempts through log analysis and implement intrusion detection systems that can identify suspicious command line argument patterns. This vulnerability aligns with tactics described in the MITRE ATT&CK framework under privilege escalation techniques, specifically targeting the use of vulnerable system utilities to gain elevated access rights. Organizations should also conduct comprehensive vulnerability assessments to identify similar format string vulnerabilities in other system utilities and applications that may be running with elevated privileges, as this class of vulnerability is particularly prevalent in legacy systems and can provide attackers with persistent access to target environments.