CVE-2012-0809 in sudo
Summary
by MITRE
Format string vulnerability in the sudo_debug function in Sudo 1.8.0 through 1.8.3p1 allows local users to execute arbitrary code via format string sequences in the program name for sudo.
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Analysis
by VulDB Data Team • 06/23/2024
The vulnerability identified as CVE-2012-0809 represents a critical format string vulnerability within the sudo command execution framework. This flaw exists in sudo versions 1.8.0 through 1.8.3p1 where the sudo_debug function fails to properly sanitize user-provided input when processing program names. The vulnerability stems from improper handling of format specifiers that allows attackers to manipulate the printf function's behavior during debug output generation. When sudo processes a program name containing format string sequences such as %s, %d, or %x, the debug function interprets these as format specifiers rather than literal characters, creating opportunities for malicious code execution.
The technical exploitation of this vulnerability occurs through the manipulation of the program name parameter passed to sudo, which then gets processed by the sudo_debug function without proper input validation. This flaw falls under CWE-134, which specifically addresses the use of format strings without proper validation, making it susceptible to both information disclosure and arbitrary code execution attacks. Attackers can leverage this vulnerability to overwrite memory locations, inject malicious code, or execute arbitrary commands with elevated privileges. The vulnerability is particularly dangerous because it allows local users to gain root access through a simple format string attack vector.
The operational impact of CVE-2012-0809 extends beyond immediate privilege escalation, as it can be exploited to compromise entire systems that rely on sudo for privilege management. This vulnerability affects systems where sudo is used to grant elevated permissions, making it a prime target for attackers seeking to establish persistent access. The exploitability is enhanced by the fact that the vulnerability requires no special privileges to trigger, as the sudo_debug function is invoked during normal sudo operations. From an attack perspective, this vulnerability aligns with ATT&CK technique T1068, which involves exploiting legitimate credentials and privileges to gain system access, and T1059, which covers command and scripting interpreters for execution.
Mitigation strategies for this vulnerability require immediate patching of affected sudo versions to 1.8.3p2 or later, which contains the necessary fixes for the format string handling. System administrators should also implement additional security controls such as restricting sudo access through proper configuration files, monitoring for unusual debug output patterns, and employing privilege separation techniques. The vulnerability demonstrates the critical importance of proper input validation in security-critical applications and serves as a reminder of the necessity for thorough code review processes. Organizations should also consider implementing automated vulnerability scanning tools that can detect similar format string vulnerabilities in other applications and systems.