CVE-2022-0617 in Linux
Summary
by MITRE • 02/16/2022
A flaw null pointer dereference in the Linux kernel UDF file system functionality was found in the way user triggers udf_file_write_iter function for the malicious UDF image. A local user could use this flaw to crash the system. Actual from Linux kernel 4.2-rc1 till 5.17-rc2.
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Analysis
by VulDB Data Team • 05/18/2025
The vulnerability identified as CVE-2022-0617 represents a critical null pointer dereference flaw within the Linux kernel's Universal Disk Format UDF file system implementation. This security issue affects kernel versions ranging from 4.2-rc1 through 5.17-rc2, creating a substantial window of exposure for systems running affected kernel versions. The flaw manifests specifically when the udf_file_write_iter function processes malicious UDF image files, demonstrating how file system implementations can become attack vectors for system compromise.
The technical nature of this vulnerability stems from inadequate input validation within the UDF file system driver, where the udf_file_write_iter function fails to properly handle null pointer references during file write operations. When a local user presents a specially crafted malicious UDF image to the system, the kernel's UDF implementation attempts to dereference a null pointer, resulting in an immediate system crash. This null pointer dereference represents a classic software bug pattern that aligns with CWE-476, which specifically addresses null pointer dereference conditions in software implementations. The vulnerability operates at the kernel level, making it particularly dangerous as it can be exploited by any local user with access to the system.
The operational impact of CVE-2022-0617 extends beyond simple system instability, as it provides a reliable method for local privilege escalation and denial of service attacks. Since the vulnerability requires only local access to trigger, it can be exploited by unprivileged users to cause system crashes, potentially leading to service disruption or system downtime. This type of vulnerability falls under the ATT&CK technique T1499.004, which involves network disruption through system resource exhaustion or crashes, though in this case the disruption occurs through direct kernel memory access manipulation. The vulnerability's exploitation path demonstrates how file system implementations can be leveraged for system compromise, particularly in environments where local users have access to storage devices or file system operations.
Mitigation strategies for this vulnerability primarily focus on kernel version updates, as the flaw was addressed in subsequent kernel releases beyond version 5.17-rc2. System administrators should prioritize upgrading to kernel versions that contain the appropriate patches, which typically include proper null pointer checks and validation within the udf_file_write_iter function. Additionally, implementing proper file system access controls and monitoring for unusual UDF file operations can help detect potential exploitation attempts. The vulnerability's classification as a kernel-level null pointer dereference also suggests that runtime monitoring tools and kernel hardening measures such as stack canaries and address space layout randomization may provide additional protection layers against exploitation attempts. Organizations should also consider implementing least privilege principles to limit local user access to file system operations that could potentially trigger such vulnerabilities.