CVE-2018-10914 in GlusterFS
Summary
by MITRE
It was found that an attacker could issue a xattr request via glusterfs FUSE to cause gluster brick process to crash which will result in a remote denial of service. If gluster multiplexing is enabled this will result in a crash of multiple bricks and gluster volumes.
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Analysis
by VulDB Data Team • 05/07/2023
The vulnerability identified as CVE-2018-10914 represents a critical remote denial of service flaw within the GlusterFS distributed file system implementation. This issue affects the FUSE (Filesystem in Userspace) component of GlusterFS, specifically targeting the brick process that handles file system operations. The vulnerability stems from insufficient input validation and error handling within the extended attributes (xattr) processing mechanism, creating a pathway for malicious actors to exploit the system through carefully crafted requests.
The technical exploitation of this vulnerability occurs when an attacker sends a specially crafted xattr request through the GlusterFS FUSE interface to a target brick process. The flaw lies in how the system processes these extended attribute operations without proper bounds checking or sanitization of input parameters. When the brick process encounters malformed or unexpected xattr data, it fails to handle the error gracefully and instead crashes the entire process. This behavior is particularly concerning because GlusterFS brick processes are fundamental components responsible for storing and managing file data across distributed storage clusters.
The operational impact of CVE-2018-10914 extends beyond single brick failures to encompass entire GlusterFS volumes when multiplexing is enabled. In environments where multiple bricks are configured for load balancing or redundancy, a single successful attack can cascade across the entire storage infrastructure, causing widespread service disruption. This multiplicative effect transforms what might initially appear as a localized crash into a system-wide denial of service condition that can persist until manual intervention restores the affected brick processes. The vulnerability directly maps to CWE-20, "Improper Input Validation," and CWE-129, "Improper Validation of Array Index," as the system fails to properly validate the size and content of extended attribute requests before processing them.
The remote nature of this vulnerability means that attackers can exploit it from any location with network access to the GlusterFS FUSE mount points, making it particularly dangerous in cloud and distributed computing environments. This characteristic aligns with ATT&CK technique T1499.004, "Endpoint Denial of Service," and demonstrates how storage system vulnerabilities can be leveraged for broader operational disruption. Organizations using GlusterFS in production environments face significant risk of service degradation or complete data access failure when this vulnerability is exploited, potentially affecting thousands of concurrent users or applications dependent on the storage infrastructure.
Mitigation strategies for CVE-2018-10914 should include immediate patching of affected GlusterFS versions, implementing network segmentation to limit access to FUSE mount points, and configuring proper firewall rules to restrict xattr operations. System administrators should also consider disabling multiplexing features if they are not essential for operations, as this reduces the potential blast radius of a successful attack. Additionally, monitoring solutions should be implemented to detect unusual patterns of xattr requests that might indicate exploitation attempts, providing early warning capabilities to prevent service disruption. The vulnerability underscores the importance of proper input validation in distributed storage systems and highlights the need for robust error handling mechanisms in file system implementations to prevent single points of failure that can cascade throughout entire storage infrastructures.