CVE-2011-4126 in Calibre
Summary
by MITRE • 10/27/2021
Race condition issues were found in Calibre at devices/linux_mount_helper.c allowing unprivileged users the ability to mount any device to anywhere.
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Analysis
by VulDB Data Team • 10/31/2021
The vulnerability identified as CVE-2011-4126 represents a critical race condition flaw within the Calibre document management system, specifically within the linux_mount_helper.c component. This issue arises from improper synchronization mechanisms during device mounting operations, creating a window where malicious users can exploit temporal inconsistencies in the system's mounting process. The race condition occurs when multiple processes or threads attempt to access shared resources simultaneously without proper locking mechanisms, allowing unauthorized manipulation of mount operations.
The technical exploitation of this vulnerability stems from the lack of adequate access controls and validation within the device mounting helper functionality. When unprivileged users can manipulate mount points through race conditions, they gain the ability to mount any available device to any location within the file system hierarchy. This flaw fundamentally undermines the system's security model by allowing users to bypass normal mount restrictions and potentially access restricted file systems or devices that should be protected from unauthorized access.
From an operational perspective, this vulnerability presents a significant risk to system integrity and data confidentiality. Attackers can leverage the race condition to mount malicious or unauthorized devices to critical system directories, potentially leading to privilege escalation or information disclosure. The impact extends beyond simple unauthorized mounting as it can enable attackers to manipulate the system's file system structure, potentially creating persistent access mechanisms or interfering with legitimate system operations. This vulnerability directly violates the principle of least privilege and can compromise the overall security posture of systems running vulnerable versions of Calibre.
The flaw aligns with CWE-362, which describes race conditions that can lead to security vulnerabilities, and represents a classic example of improper resource management in concurrent systems. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be used to establish persistence within affected systems. The attack surface is particularly concerning as it allows for mounting operations that bypass normal user permissions and system controls. Organizations should implement immediate mitigations including updating to patched versions of Calibre, implementing proper access controls, and monitoring for unauthorized mounting activities. System administrators should also consider restricting access to mount helper utilities and implementing additional security controls around device mounting operations to prevent exploitation of this race condition vulnerability.