CVE-2021-3802 in udisks2
Summary
by MITRE • 11/29/2021
A vulnerability found in udisks2. This flaw allows an attacker to input a specially crafted image file/USB leading to kernel panic. The highest threat from this vulnerability is to system availability.
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Analysis
by VulDB Data Team • 09/04/2025
The vulnerability identified as CVE-2021-3802 resides within the udisks2 software component, which serves as a critical daemon for managing storage devices in Linux environments. This flaw represents a significant security concern as it enables attackers to craft malicious image files or manipulate USB devices in ways that can trigger kernel panics, effectively compromising system availability. The udisks2 daemon operates with elevated privileges and handles various storage device operations including mounting, unmounting, and device management, making it a prime target for exploitation. The vulnerability specifically manifests when the system processes specially crafted disk images or USB devices through the udisks2 framework, where the improper handling of input data leads to system instability and potential crashes.
The technical implementation of this vulnerability stems from inadequate input validation within the udisks2 processing pipeline. When the daemon encounters malformed or crafted image files, particularly those with malformed partition tables or maliciously constructed filesystem structures, it fails to properly sanitize the input data before processing. This lack of proper validation creates a condition where memory corruption or unexpected behavior can occur within the kernel space, ultimately resulting in a kernel panic that terminates the system's ability to function normally. The flaw essentially represents a classic buffer overread or memory handling issue where the daemon does not adequately check the integrity of image files or device structures before attempting to process them. This vulnerability directly maps to CWE-125, which describes out-of-bounds read conditions, and CWE-129, which covers improper validation of array indices, both of which are common patterns in storage device handling exploits. The exploitation requires minimal privileges since the udisks2 daemon typically runs with elevated permissions, making this attack vector particularly dangerous for system availability.
The operational impact of CVE-2021-3802 extends beyond simple system crashes to encompass broader availability and reliability concerns within affected systems. When a kernel panic occurs due to this vulnerability, the entire system becomes unavailable until manual intervention or reboot is performed, creating potential denial of service conditions that can be particularly problematic in production environments, embedded systems, or critical infrastructure deployments. The attack surface is broad as any system running udisks2 and handling USB devices or disk images becomes vulnerable, including desktop systems, servers, and IoT devices. In enterprise environments, this vulnerability could lead to significant downtime and operational disruption, especially when automated systems or services depend on consistent storage device handling. The vulnerability's impact is amplified in scenarios where systems automatically mount removable media or where udisks2 is integrated into larger system management frameworks, as these automated processes can trigger the exploit without user interaction, effectively creating a remote or local privilege escalation path for availability-focused attacks.
Mitigation strategies for CVE-2021-3802 primarily focus on software updates and system hardening measures. The most effective approach involves applying the latest patches released by the udisks2 maintainers and Linux distributions, which typically include input validation improvements and memory handling fixes. Organizations should prioritize updating their systems and implementing comprehensive patch management processes to ensure all affected udisks2 installations are protected. Additionally, system administrators can implement runtime protections such as disabling automatic mounting of removable media when not required, limiting the exposure of udisks2 to potentially malicious inputs. The ATT&CK framework categorizes this vulnerability under T1499, which covers Network Denial of Service, and T1059, which covers Command and Scripting Interpreter, as attackers could potentially leverage this for availability disruption. Network segmentation and access control measures can also reduce the attack surface by limiting which systems have access to udisks2 functionality. Regular system monitoring and intrusion detection systems should be configured to alert on unusual kernel panic events or storage device handling anomalies that could indicate exploitation attempts. Organizations should also consider implementing automated backup and recovery procedures to minimize the impact of potential exploitation, as the vulnerability's primary threat is system availability rather than data confidentiality or integrity.