CVE-2005-0201 in d-bus
Summary
by MITRE
d-bus (dbus) before 0.22 does not properly restrict access to a socket if the socket address is known which allows local users to listen or send arbitrary messages on another user s per-user session bus via that socket.
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Analysis
by VulDB Data Team • 07/05/2025
The vulnerability identified as CVE-2005-0201 affects the dbus message bus system version 0.22 and earlier, presenting a critical security flaw in the Unix domain socket access control mechanisms. This issue specifically targets the per-user session bus implementation where dbus manages communication between applications and system services. The flaw stems from inadequate socket access restrictions that allow local users to exploit known socket addresses to gain unauthorized access to other users' session buses. The vulnerability exists because dbus fails to properly validate socket permissions and access controls when handling socket connections, creating a pathway for privilege escalation and information disclosure attacks. The technical root cause can be categorized under CWE-284, which addresses improper access control mechanisms, and specifically relates to insufficient checks on Unix domain socket permissions.
The operational impact of this vulnerability is severe as it enables local privilege escalation attacks where malicious users can eavesdrop on communications or inject arbitrary messages into other users' session buses. Attackers with local access can leverage this flaw to monitor sensitive communications between applications and system services, potentially gaining access to confidential data, session tokens, or other sensitive information transmitted through the bus. The vulnerability affects the core security model of dbus by undermining the isolation between user sessions, allowing cross-user interference that violates fundamental security principles of process isolation. This type of attack falls under the ATT&CK technique T1068, which involves exploiting legitimate credentials and access to gain system privileges. The attack vector requires local system access and knowledge of the target user's socket address, making it particularly dangerous in multi-user environments where users share the same system resources.
Mitigation strategies for this vulnerability involve upgrading to dbus version 0.22 or later where proper socket access controls have been implemented. System administrators should ensure all dbus components are updated to versions that properly enforce socket permissions and access restrictions. Additionally, implementing proper network segmentation and access controls can help limit the attack surface, though the primary solution requires addressing the core software vulnerability. Security monitoring should include detection of unauthorized socket access patterns and unusual communication behavior on session buses. The fix implemented in newer versions of dbus typically involves strengthening the socket permission checks during connection establishment and ensuring that only authorized processes can access specific session bus sockets. Organizations should also consider implementing additional security measures such as mandatory access controls and process monitoring to detect potential exploitation attempts. This vulnerability highlights the importance of proper access control implementation in inter-process communication systems and serves as a reminder that even seemingly simple socket operations require rigorous security validation to prevent privilege escalation attacks.