CVE-2018-19358 in Keyring
Summary
by MITRE
GNOME Keyring through 3.28.2 allows local users to retrieve login credentials via a Secret Service API call and the D-Bus interface if the keyring is unlocked, a similar issue to CVE-2008-7320. One perspective is that this occurs because available D-Bus protection mechanisms (involving the busconfig and policy XML elements) are not used.
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Analysis
by VulDB Data Team • 08/05/2024
The vulnerability identified as CVE-2018-19358 represents a significant security weakness in the GNOME Keyring system that affects versions through 3.28.2. This flaw enables local attackers to extract stored login credentials through the Secret Service API and D-Bus interface when the keyring is already unlocked. The vulnerability operates at the intersection of desktop security management and inter-process communication, creating a pathway for privilege escalation and credential theft within the local system environment. The issue demonstrates a fundamental flaw in how the system handles access control for sensitive credential storage mechanisms.
The technical implementation of this vulnerability stems from insufficient access controls within the D-Bus communication framework that GNOME Keyring utilizes. When a user unlocks their keyring, the system should enforce strict access controls to prevent unauthorized applications from querying stored credentials through the Secret Service API. However, the vulnerability occurs because the D-Bus protection mechanisms that should restrict access are either not properly configured or not being utilized at all. This failure in access control enforcement allows any local application to make Secret Service API calls and retrieve stored passwords, usernames, and other sensitive authentication data without proper authorization. The vulnerability is categorized under CWE-284 which specifically addresses improper access control, making it a clear example of insufficient privilege checks in the system.
The operational impact of CVE-2018-19358 extends beyond simple credential theft to potentially enable broader system compromise. An attacker with local access can leverage this vulnerability to obtain stored passwords for various services including email accounts, web applications, and network services. This creates a persistent threat vector where attackers can maintain access to systems and services even after initial compromise. The vulnerability is particularly concerning because it operates at the desktop level where users typically trust applications and do not expect such granular access control failures. The similarity to CVE-2008-7320 demonstrates that this is a long-standing architectural issue in how desktop credential managers handle D-Bus access controls, indicating that the problem has persisted through multiple system updates and security improvements.
The mitigation strategies for this vulnerability involve implementing proper D-Bus access control policies that restrict which applications can query the Secret Service API. System administrators should ensure that D-Bus configuration files properly define access restrictions using busconfig and policy XML elements that limit access to authorized applications only. The recommended approach includes configuring appropriate security policies that require applications to have proper authorization before accessing the keyring through D-Bus interfaces. Additionally, users should be encouraged to lock their keyrings when not actively using them, though this does not fully address the underlying access control issue. From an ATT&CK perspective, this vulnerability maps to T1555.005 which covers credential access through the secret service API, and T1068 which involves exploiting local privileges to gain unauthorized access to system resources. The vulnerability also aligns with the principle of least privilege enforcement and demonstrates the critical importance of proper inter-process communication security in desktop environments.