CVE-2014-3477 in D-Bus
Summary
by MITRE
The dbus-daemon in D-Bus 1.2.x through 1.4.x, 1.6.x before 1.6.20, and 1.8.x before 1.8.4, sends an AccessDenied error to the service instead of a client when the client is prohibited from accessing the service, which allows local users to cause a denial of service (initialization failure and exit) or possibly conduct a side-channel attack via a D-Bus message to an inactive service.
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Analysis
by VulDB Data Team • 01/17/2025
The vulnerability identified as CVE-2014-3477 resides within the D-Bus message bus system, specifically in the dbus-daemon component that manages communication between applications on Linux systems. This issue affects multiple versions of the D-Bus daemon including 1.2.x through 1.4.x, 1.6.x before 1.6.20, and 1.8.x before 1.8.4, representing a significant portion of the D-Bus ecosystem that powers inter-process communication across numerous Linux distributions and desktop environments. The flaw manifests in the daemon's error handling mechanism when processing access control decisions, creating a critical security gap that can be exploited by local attackers to manipulate the system's service availability and potentially extract information through side-channel analysis.
The technical implementation of this vulnerability stems from an incorrect error response mechanism within the D-Bus daemon. When a client attempts to access a service that it is not authorized to reach, the daemon should properly respond with an AccessDenied error directed to the client to indicate the access violation. However, in affected versions, the daemon incorrectly sends this AccessDenied error to the service itself rather than to the requesting client. This misdirection occurs during the service activation and access control validation process, where the daemon's authorization logic fails to properly distinguish between client and service contexts when generating error responses. The flaw operates at the protocol level of D-Bus communication, specifically affecting how the daemon handles service access control decisions and error propagation.
The operational impact of this vulnerability extends beyond simple denial of service conditions, creating both immediate availability issues and potential information leakage risks. Local attackers can exploit this weakness to cause daemon initialization failures and subsequent process exits, effectively disrupting the D-Bus messaging infrastructure that numerous system components depend upon for proper operation. This can result in cascading failures where applications that rely on D-Bus communication cease to function correctly, potentially affecting desktop environments, system services, and background processes. Additionally, the improper error handling creates opportunities for side-channel attacks where an attacker might infer information about service availability or access control status by observing the daemon's behavior and error responses, potentially revealing system configuration details or access patterns that should remain hidden.
From a cybersecurity perspective, this vulnerability aligns with CWE-284, which addresses improper access control issues in software systems, and represents a classic case of incorrect privilege management within a communication framework. The ATT&CK framework categorizes this as a privilege escalation technique through service manipulation, as local adversaries can leverage the flawed error handling to gain control over service initialization processes and potentially escalate their access level. The vulnerability's exploitation requires local system access but provides significant control over the messaging infrastructure, making it particularly dangerous in multi-user environments where local privilege escalation can lead to broader system compromise. Organizations should prioritize patching affected systems to prevent exploitation, as the vulnerability can be leveraged to create persistent availability issues or as a stepping stone for more sophisticated attacks targeting the broader system infrastructure that relies on D-Bus for inter-process communication.