CVE-2010-0426 in sudo
Summary
by MITRE
sudo 1.6.x before 1.6.9p21 and 1.7.x before 1.7.2p4, when a pseudo-command is enabled, permits a match between the name of the pseudo-command and the name of an executable file in an arbitrary directory, which allows local users to gain privileges via a crafted executable file, as demonstrated by a file named sudoedit in a user's home directory.
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Analysis
by VulDB Data Team • 05/01/2026
The vulnerability identified as CVE-2010-0426 represents a critical privilege escalation flaw in the sudo command utility affecting versions 1.6.x prior to 1.6.9p21 and 1.7.x prior to 1.7.2p4. This issue stems from improper handling of pseudo-commands within the sudo execution framework, creating a dangerous condition where local attackers can manipulate the command resolution process to execute malicious code with elevated privileges. The vulnerability specifically manifests when pseudo-commands are enabled, which are special sudo features designed to provide additional functionality beyond simple command execution.
The technical flaw exploits a path traversal and command name matching vulnerability in sudo's command resolution logic. When a pseudo-command is enabled, sudo attempts to match the command name against available executables in the system PATH. However, the implementation fails to properly validate or sanitize the command name resolution process, allowing attackers to place malicious executable files with the same name as pseudo-commands in arbitrary directories. The vulnerability is particularly dangerous because it leverages the sudoedit pseudo-command, which is commonly enabled in many Unix-like systems. Attackers can place a malicious sudoedit executable in their home directory, and when sudo attempts to resolve the command, it will execute the attacker-controlled file instead of the legitimate system sudoedit utility.
This vulnerability operates under the attack pattern described in the ATT&CK framework as privilege escalation through exploitation of software vulnerabilities, specifically targeting the 'Exploitation for Privilege Escalation' tactic. The flaw aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, and CWE-78, which covers improper neutralization of special elements used in OS commands. The vulnerability enables local users to bypass the normal sudo security controls and execute commands with root privileges, effectively compromising the entire system's security posture.
The operational impact of CVE-2010-0426 is severe and far-reaching, as it allows any local user with access to the system to escalate their privileges to root level without requiring authentication. This creates an immediate and significant threat to system integrity, as attackers can execute arbitrary code with the highest system privileges, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it can be exploited without any special privileges beyond basic user access, and the exploitation requires minimal technical knowledge. Systems where sudoedit or similar pseudo-commands are enabled are at risk, which includes most Unix-like systems that implement sudo for privilege management. The attack vector is straightforward and reliable, making this vulnerability a prime target for both casual attackers and more sophisticated threat actors seeking to establish persistent access to systems.
Mitigation strategies for this vulnerability involve immediate patching of affected sudo versions to the secure releases 1.6.9p21 and 1.7.2p4 respectively, which contain the necessary fixes to properly validate command name resolution and prevent the pseudo-command name matching exploit. Organizations should also review their sudo configuration files to disable unnecessary pseudo-commands when possible, particularly sudoedit, which is the primary target of this attack. Additional defensive measures include implementing proper file system permissions and access controls, monitoring for suspicious executable files in user directories, and conducting regular security audits of sudo configurations. The fix implemented in the patched versions addresses the core issue by ensuring that pseudo-commands are properly resolved against predefined system paths rather than allowing arbitrary directory traversal, thereby preventing the malicious executable placement attack pattern.