CVE-2023-2513 in Linux
Summary
by MITRE • 05/09/2023
A use-after-free vulnerability was found in the Linux kernel's ext4 filesystem in the way it handled the extra inode size for extended attributes. This flaw could allow a privileged local user to cause a system crash or other undefined behaviors.
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Analysis
by VulDB Data Team • 12/18/2025
The vulnerability identified as CVE-2023-2513 represents a critical use-after-free condition within the linux kernel's ext4 filesystem implementation that specifically impacts how the system manages extended attributes and inode structures. This flaw exists in the kernel's handling of extra inode size parameters when processing extended filesystem attributes, creating a scenario where memory that has been freed is subsequently accessed by the system. The vulnerability stems from improper memory management practices during the processing of extended attributes within the ext4 filesystem driver, where the kernel fails to properly validate or manage the lifecycle of memory regions associated with inode structures. The issue manifests when the kernel attempts to manipulate extended attributes that are stored in larger inode structures, leading to a situation where freed memory locations are accessed by subsequent operations.
From a technical perspective, this use-after-free vulnerability operates at the kernel level within the ext4 filesystem subsystem and directly relates to CWE-416 which specifically addresses use-after-free conditions in software systems. The flaw occurs during the processing of extended attributes when the kernel allocates memory for inode structures that may contain extended attribute data, and subsequently frees this memory without proper invalidation of references. When the system later attempts to access these freed memory regions during extended attribute operations, the kernel experiences undefined behavior that can result in system crashes, data corruption, or potentially exploitable conditions. The vulnerability is particularly concerning because it affects the core filesystem operations that are fundamental to system stability and data integrity.
The operational impact of CVE-2023-2513 extends beyond simple system crashes to encompass potential privilege escalation scenarios and system instability that can affect the entire kernel operation. A privileged local user with access to the system can exploit this vulnerability to cause denial of service conditions that may result in complete system crashes or data corruption within the affected filesystem. The nature of use-after-free vulnerabilities makes them particularly dangerous because they can potentially be leveraged for more sophisticated attacks if the freed memory can be manipulated to contain malicious data. The vulnerability affects systems running linux kernels that implement ext4 filesystem with extended attribute support, which represents a significant portion of modern linux deployments. The impact is particularly severe in server environments where filesystem stability and data integrity are paramount, as this flaw could lead to complete system outages or data loss scenarios.
Mitigation strategies for CVE-2023-2513 should focus on immediate kernel updates and patches provided by linux kernel maintainers, as the vulnerability requires core kernel modifications to address the memory management issues. System administrators should prioritize applying the official kernel patches that fix the specific memory handling routines in the ext4 filesystem driver, particularly those addressing the extended attribute processing and inode structure management. The vulnerability does not require special privileges to exploit beyond normal user access, making it particularly dangerous in multi-user environments where local privilege escalation could occur. Organizations should also implement monitoring systems to detect potential exploitation attempts through unusual filesystem access patterns or system crash reports. Additionally, the vulnerability highlights the importance of kernel security testing and memory safety validation in filesystem implementations, aligning with ATT&CK technique T1068 which addresses privilege escalation through kernel vulnerabilities. Regular security audits of kernel modules and filesystem implementations should be conducted to identify similar memory management flaws that could potentially be exploited in similar ways.