CVE-2011-4406 in Ubuntu Linux
Summary
by MITRE
The Ubuntu AccountsService package before 0.6.14-1git1ubuntu1.1 does not properly drop privileges when changing language settings, which allows local users to modify arbitrary files via unspecified vectors.
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Analysis
by VulDB Data Team • 05/11/2026
The vulnerability identified as CVE-2011-4406 resides within the Ubuntu AccountsService package, specifically affecting versions prior to 0.6.14-1git1ubuntu1.1. This issue represents a privilege escalation weakness that fundamentally undermines the security model of the system by allowing local attackers to manipulate critical system files through language configuration changes. The AccountsService package serves as a central component for managing user accounts and system preferences in Ubuntu environments, making it a prime target for attackers seeking persistent access or system compromise.
The technical flaw manifests in the improper privilege dropping mechanism during language setting modifications, which constitutes a violation of the principle of least privilege. When users attempt to change language preferences through the AccountsService, the system fails to adequately demote its privileges before executing file modification operations. This vulnerability falls under the category of privilege escalation as defined by CWE-269, specifically CWE-269: "Improper Privilege Management" and CWE-782: "Exposed Runnable Scheduler" when considering the execution context. The unspecified vectors mentioned in the description suggest that attackers can leverage multiple attack paths to exploit this weakness, potentially including direct file system manipulation or indirect exploitation through other system components that rely on AccountsService functionality.
The operational impact of this vulnerability extends beyond simple file modification capabilities, as it provides attackers with the means to potentially escalate their privileges to root level access or modify critical system configuration files. Local users who can access the AccountsService interface can exploit this weakness to overwrite system files, inject malicious code, or alter user permissions, creating persistent backdoors or compromising the integrity of the entire system. The vulnerability particularly affects Ubuntu systems where AccountsService is actively running and where users have local access to modify language settings. Attackers could leverage this to modify configuration files, inject malicious code into system binaries, or manipulate user account data, leading to complete system compromise.
Mitigation strategies for CVE-2011-4406 primarily involve upgrading to the patched version of the AccountsService package, specifically version 0.6.14-1git1ubuntu1.1 or later, which properly implements privilege dropping mechanisms. System administrators should also consider implementing additional security controls such as monitoring for unauthorized language setting changes and reviewing system logs for suspicious file modification patterns. The vulnerability demonstrates the importance of proper privilege management in system services and aligns with ATT&CK technique T1068: "Local Port Forwarding" and T1548.001: "Abuse Elevation Control Mechanism" when attackers exploit such weaknesses to gain higher privileges. Organizations should also consider implementing the principle of least privilege for all system services and regularly auditing service configurations to prevent similar issues from arising in other components of the system infrastructure.