CVE-2022-48665 in Linux
Summary
by MITRE • 04/28/2024
In the Linux kernel, the following vulnerability has been resolved:
exfat: fix overflow for large capacity partition
Using int type for sector index, there will be overflow in a large capacity partition.
For example, if storage with sector size of 512 bytes and partition capacity is larger than 2TB, there will be overflow.
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Analysis
by VulDB Data Team • 09/18/2025
The vulnerability identified as CVE-2022-48665 represents a critical integer overflow issue within the exFAT filesystem driver of the Linux kernel. This flaw specifically manifests when processing storage devices with large capacity partitions where the sector index calculation exceeds the maximum value that can be represented by the int data type. The exFAT filesystem implementation uses a 32-bit signed integer to track sector indices during partition operations, which creates a fundamental limitation when dealing with modern storage devices that exceed certain capacity thresholds.
The technical implementation of this vulnerability stems from the kernel's exFAT driver failing to properly handle sector indexing calculations for partitions exceeding 2 terabytes in capacity when using a standard 512-byte sector size. When the sector index calculation surpasses the maximum value of a 32-bit signed integer, typically 2,147,483,647, the integer overflow occurs and wraps around to negative values or unexpected positive numbers. This overflow condition fundamentally breaks the filesystem's ability to correctly map and access sectors within the partition, creating a scenario where legitimate sector operations can fail or produce incorrect results.
The operational impact of this vulnerability extends beyond simple read/write failures to potentially compromise data integrity and system stability. Attackers could exploit this condition to cause denial of service through filesystem corruption or manipulation of sector access patterns. The vulnerability affects systems running Linux kernels that include the exFAT filesystem driver and are handling large capacity storage devices. Systems with storage larger than 2TB that utilize exFAT filesystems are particularly at risk, as the overflow condition becomes inevitable when the sector index exceeds the integer capacity.
This vulnerability aligns with CWE-190, Integer Overflow or Wraparound, which specifically addresses issues where integer arithmetic operations produce results that exceed the maximum value representable by the data type. The flaw also intersects with ATT&CK technique T1490, Data Destruction, as the overflow could potentially lead to filesystem corruption and data loss. Additionally, the vulnerability demonstrates characteristics of T1070, Indicator Removal on Host, as the overflow may cause the system to behave unpredictably, potentially masking other security issues or making forensic analysis more difficult.
Mitigation strategies for this vulnerability primarily involve upgrading to patched Linux kernel versions that address the integer overflow in the exFAT driver implementation. System administrators should prioritize kernel updates that include the specific fix for CVE-2022-48665, which typically involves changing the sector index data type from int to a larger integer type such as long or uint64_t to accommodate larger capacity partitions. Organizations should also implement monitoring for filesystem access patterns that might trigger the overflow condition and consider implementing additional filesystem validation checks for large capacity devices. The fix ensures that sector indexing calculations can properly handle partitions of any reasonable size without integer wraparound issues, thereby maintaining filesystem integrity and preventing potential exploitation scenarios.