Cyber Resilience

CVE-2025-20711

Memory Safety in Openwrt 19.07.0 … 21.02.0

Published
14 October 2025
Modified
16 October 2025
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0029 21th percentile
Risk Priority 63 floored blend · peak EPSS

Summary

CVE-2025-20711 is a high-severity Improper Validation of Specified Type of Input (CWE-1287) vulnerability in Mediatek Mt6890. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 21th 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 SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In wlan AP driver, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.…

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Patch ID: WCNCR00422399; Issue ID: MSV-3748.

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.

CVEs Like This One

CVE-2025-20654Same product: Mediatek Mt6890
CVE-2024-20017Same product: Mediatek Mt6890
CVE-2024-20073Same product: Mediatek Mt6890
CVE-2024-20072Same product: Mediatek Mt6890
CVE-2025-20646Same product: Mediatek Mt6890
CVE-2025-20631Same product: Mediatek Mt7916
CVE-2025-20632Same product: Mediatek Mt7916
CVE-2023-20775Same product: Mediatek Mt6890
CVE-2024-20006Same product: Mediatek Mt6890
CVE-2024-20018Same product: Mediatek Software Development Kit

Affected Assets

mediatek
software development kit
≤ 7.6.7.2
openwrt
openwrt
19.07.0, 21.02.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.1.1
  • V1.4.2
  • V2.1.1
  • V2.2.2

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including fuzzing and bounds checks) finds out-of-bounds write flaws before deployment.

SI-10 directly requires validation of information inputs, which structurally prevents type-validation failures from being introduced or exploitable.

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

Memory-protection mechanisms limit the exploitability and blast radius of a successful out-of-bounds write.

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 SDLC practices directly require proper input type validation during development.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

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 can detect type-validation flaws but does not prevent them during development.

prevents

Secure development lifecycle mandates input validation and type checking to prevent improper type handling.

prevents

Application security requirements explicitly include validation of input data types and formats.

prevents

Secure architecture principles promote defensive input handling and type enforcement at system boundaries.

prevents

Secure coding standards directly require proper type validation of all external inputs.

prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References