Linux Kernel up to 6.13.3/6.14-rc2 uring_cmd information disclosure

Summaryinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.13.3/6.14-rc2. This vulnerability affects unknown code of the component uring_cmd. Such manipulation leads to information disclosure. This vulnerability is listed as CVE-2025-21837. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Linux Kernel up to 6.13.3/6.14-rc2. Affected by this issue is an unknown function of the component uring_cmd. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: io_uring/uring_cmd: unconditionally copy SQEs at prep time This isn't generally necessary, but conditions have been observed where SQE data is accessed from the original SQE after prep has been done and outside of the initial issue. Opcode prep handlers must ensure that any SQE related data is stable beyond the prep phase, but uring_cmd is a bit special in how it handles the SQE which makes it susceptible to reading stale data. If the application has reused the SQE before the original completes, then that can lead to data corruption. Down the line we can relax this again once uring_cmd has been sanitized a bit, and avoid unnecessarily copying the SQE.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-21837 since 12/29/2024. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1592.

The vulnerability scanner Nessus provides a plugin with the ID 235716 (CentOS 9 : kernel-5.14.0-583.el9), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.13.4 or 6.14-rc3 eliminates this vulnerability. Applying the patch 87fe1d68842a308998b315c8ed0163a1d639017c/d6211ebbdaa541af197b50b8dd8f22642ce0b87f is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (235716) and CERT Bund (WID-SEC-2025-0499). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• SolarWinds Security Event Manager
• Open Source Linux Kernel
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.13.0
• 6.13.1
• 6.13.2
• 6.13.3
• 6.14-rc1
• 6.14-rc2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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