CVE-2012-2337 in sudo
Summary
by MITRE
sudo 1.6.x and 1.7.x before 1.7.9p1, and 1.8.x before 1.8.4p5, does not properly support configurations that use a netmask syntax, which allows local users to bypass intended command restrictions in opportunistic circumstances by executing a command on a host that has an IPv4 address.
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Analysis
by VulDB Data Team • 12/02/2021
The vulnerability identified as CVE-2012-2337 represents a critical flaw in the sudo command execution mechanism affecting versions 1.6.x through 1.7.9p1 and 1.8.x through 1.8.4p5. This security weakness stems from improper handling of netmask syntax configurations within sudo's privilege management system, creating a significant bypass opportunity for local attackers. The flaw specifically manifests when sudo encounters configurations utilizing netmask notation, which should theoretically restrict command execution based on network addressing parameters. However, the implementation contains a logical error that allows unauthorized privilege escalation under specific network conditions.
The technical implementation of this vulnerability occurs at the network address validation layer within sudo's configuration parsing mechanism. When sudo processes a configuration entry containing netmask syntax such as 192.168.1.0/24, the system fails to properly validate whether the executing host's IP address actually falls within the specified network range. This improper validation allows a local user to exploit the configuration by manipulating their network address or by leveraging opportunistic circumstances where the system's IP address resolution does not match the expected netmask parameters. The flaw essentially creates a path where sudo's intended access controls can be circumvented without proper authentication mechanisms being triggered.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass broader security implications for systems relying on sudo's network-based access controls. Local users who can execute commands on hosts with IPv4 addresses can bypass intended command restrictions, potentially gaining elevated privileges that should be restricted to specific users or groups. This vulnerability particularly affects systems where sudo configurations utilize netmask syntax to control access from multiple hosts within a network segment. The opportunistic nature of the exploit means that the vulnerability may not be immediately apparent during normal operations but can be triggered when specific network conditions align with the flawed validation logic.
Mitigation strategies for CVE-2012-2337 require immediate patching of affected sudo versions to the recommended secure releases, specifically upgrading to sudo 1.7.9p1 or 1.8.4p5 respectively. Organizations should also conduct comprehensive audits of their sudo configurations to identify any netmask-based restrictions that may be vulnerable to this attack vector. The remediation process involves either upgrading the sudo software to patched versions or reconfiguring existing sudoers files to avoid netmask syntax that triggers the flawed validation logic. Security teams should implement monitoring for unauthorized sudo usage patterns that might indicate exploitation attempts and establish network segmentation controls to limit the potential impact of local privilege escalation.
This vulnerability aligns with CWE-284, which addresses improper access control in software systems, and demonstrates the importance of proper input validation and privilege management in security-critical applications. The attack pattern associated with this vulnerability corresponds to techniques described in the ATT&CK framework under privilege escalation tactics, specifically targeting local user accounts to gain elevated system privileges. The vulnerability highlights the critical need for thorough testing of network-based access control mechanisms and proper validation of all input parameters within security-sensitive software components. Organizations implementing sudo-based privilege management systems should consider additional security controls such as mandatory access controls and regular privilege audits to prevent exploitation of similar configuration-based vulnerabilities.