Uninitialized Value Bug in Linux Kernel: CVE-2025-40043
Summary
DEBIAN-CVE-2025-40043: In the Linux kernel, the following vulnerability has been resolved: net: nfc: nci: Add parameter validation for packet data Syzbot reported an uninitialized value bug in nci_init_req, which was introduced by commit 5aca7... Affects linux versions 5.10.103-1 – 6.9.9-1. No fix is published. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
The Linux kernel is the core component of many operating systems, providing essential services for hardware and software interaction. It is known for its stability, performance, and security features. However, vulnerabilities can arise due to complex interactions within the kernel, such as the one identified in CVE-2025-40043, which affects the NFC (Near Field Communication) subsystem.
Vulnerability Detail
CVE-2025-40043 is a vulnerability in the Linux kernel's NFC subsystem, specifically in the nci_init_req function. This issue stems from an uninitialized value bug introduced by a recent commit, which resulted in inadequate input validation at the nic_valid_size function. The validation only checks the length of the skb (socket buffer) against the expected size, leading to potential memory access violations. This can cause the kernel to process uninitialized memory, leading to undefined behavior, crashes, or security breaches.
How To Fix
No fixed version is published for this vulnerability.
Tip — Not sure whether your app is affected? Vulert can check the versions your app actually runs. Scan free →
Workaround
Currently, there are no specific workarounds mentioned for this vulnerability. However, users can mitigate risks by ensuring that their systems are regularly updated and by monitoring for any unusual behavior in NFC-related functionalities.
Conclusion
CVE-2025-40043 represents a significant vulnerability in the Linux kernel's NFC subsystem, stemming from inadequate input validation. Users are encouraged to update their systems promptly to mitigate potential risks associated with this issue.
See every vulnerability recorded for linux →
FAQ
CVE-2025-40043 is a vulnerability in the Linux kernel's NFC subsystem that can lead to processing uninitialized memory, potentially causing crashes or security issues.
You can use Vulert, which monitors open-source vulnerabilities in your software. By uploading your manifest file, you can check for vulnerabilities like CVE-2025-40043 without needing to install any software.
While there are no specific workarounds, ensure your system is monitored for unusual behavior and consider limiting the use of NFC functionalities until a patch is applied.
This vulnerability can lead to undefined behavior in the kernel, which may allow attackers to exploit the system, potentially leading to unauthorized access or system crashes.
Detailed information about CVE-2025-40043 can be found in the Debian security advisories and the official Linux kernel documentation.
References
Related vulnerabilities
Recent vulnerabilities recorded for linux.
