Cyber Resilience

CVE-2025-21794

Memory Safety in Linux Kernel 6.6.76 – 6.6.79

Published
27 February 2025
Modified
03 November 2025
Patch / advisory
CVSS Score v3.1 7.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
EPSS Score 0.0023 13th percentile
Risk Priority 51 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2025-21794 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-21794 is a stack out-of-bounds read vulnerability in the Linux kernel's hid-thrustmaster driver. The flaw arises when the ep_addr array is passed to the usb_check_int_endpoints() function from the usb.c core driver without a null terminator at the end. This causes a for loop in usb_check_int_endpoints() to iterate beyond the array's bounds, attempting to read a non-existent element and resulting in a kernel crash. The vulnerability, associated with CWE-125, was published on 2025-02-27 and carries a CVSS v3.1 base score of 7.1 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H).

A local attacker with low privileges can exploit this vulnerability with low attack complexity and no user interaction. Exploitation triggers the out-of-bounds read during handling of Thrustmaster HID USB devices, leading to a kernel panic and denial of service. The CVSS metrics indicate potential high confidentiality impact alongside high availability impact, stemming from the nature of the stack read.

Mitigation requires updating to a patched Linux kernel version. Upstream fixes, available in stable kernel repositories, add a 0 (null) element to the end of the ep_addr array in the hid-thrustmaster driver to properly terminate the loop in usb_check_int_endpoints(). Relevant patches include commits such as 0b43d98ff29be3144e86294486b1373b5df74c0e, 436f48c864186e9413d1b7c6e91767cc9e1a65b8, and others listed in kernel.org stable trees.

The issue was detected by Syzbot, a kernel fuzzer, as detailed at https://syzkaller.appspot.com/bug?extid=9c9179ac46169c56c1ad. No real-world exploitation in the wild has been reported.

EU & UK References

Vulnerability Data

In the Linux kernel, the following vulnerability has been resolved: HID: hid-thrustmaster: fix stack-out-of-bounds read in usb_check_int_endpoints() Syzbot[1] has detected a stack-out-of-bounds read of the ep_addr array from hid-thrustmaster driver. This array is passed to usb_check_int_endpoints function from usb.c core…

more

driver, which executes a for loop that iterates over the elements of the passed array. Not finding a null element at the end of the array, it tries to read the next, non-existent element, crashing the kernel. To fix this, a 0 element was added at the end of the array to break the for loop. [1] https://syzkaller.appspot.com/bug?extid=9c9179ac46169c56c1ad

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

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Affected Assets

linux
linux kernel
6.14 · 6.6.76 — 6.6.79 · 6.12.13 — 6.12.16 · 6.13.2 — 6.13.4

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.

Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.

Process isolation confines the effects of an out-of-bounds read to the compromised process.

Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

prevents

Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.

prevents

Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.

prevents

Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.

prevents

Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.

References