Out-of-Bounds Read Vulnerability in Linux Kernel - CVE-2025-40044
Summary
DEBIAN-CVE-2025-40044: In the Linux kernel, the following vulnerability has been resolved: fs: udf: fix OOB read in lengthAllocDescs handling When parsing Allocation Extent Descriptor, lengthAllocDescs comes from on-disk data and must be valid... Affects linux versions 5.10.103-1 – 6.9.9-1. No fix is published. How to fix ↓
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Background
The Linux kernel is the core component of many operating systems, providing the essential interface between computer hardware and software. It manages system resources, facilitates communication between hardware and applications, and ensures system stability and security. This vulnerability, identified as CVE-2025-40044, affects the UDF (Universal Disk Format) file system within the Linux kernel, which is responsible for managing file storage on optical media. The vulnerability arises from improper validation of on-disk data, potentially leading to severe security implications.
Vulnerability Detail
In the Linux kernel, a vulnerability has been identified in the handling of Allocation Extent Descriptors within the UDF file system. Specifically, the lengthAllocDescs value, which is derived from on-disk data, is not adequately validated against the block size. This oversight allows crafted or corrupted images to set lengthAllocDescs in such a way that the total descriptor length exceeds the allocated buffer. As a result, the udf_update_tag() function may invoke crc_itu_t() on out-of-bounds memory, leading to a KASAN (Kernel Address Sanitizer) use-after-free read. This can cause system instability and potential exploitation by malicious actors.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a temporary workaround, users can avoid using UDF file systems with potentially corrupted images until the kernel is updated. Additionally, ensuring that only trusted images are used can help mitigate the risk of exploitation.
Conclusion
CVE-2025-40044 represents a significant vulnerability within the Linux kernel's UDF file system, with the potential for serious security implications. Users are strongly encouraged to update their systems to the patched version of the kernel to mitigate risks. Understanding and addressing such vulnerabilities is crucial for maintaining system integrity and security.
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FAQ
CVE-2025-40044 is a vulnerability in the Linux kernel's UDF file system that can lead to out-of-bounds memory access.
Exploitation of this vulnerability can lead to system crashes, data corruption, or unauthorized access to sensitive information.
Yes, a patch has been released, and users are advised to update their Linux kernel to the latest version.
As a temporary measure, avoid using UDF file systems with untrusted or potentially corrupted images.
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References
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