CVE-2025-65226
Memory Safety in Tenda Ac21 Firmware 16.03.08.16
Raw vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LSummary
CVE-2025-65226 is a medium-severity Classic Buffer Overflow (CWE-120) vulnerability in Tenda Ac21 Firmware. Its CVSS base score is 4.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-16 (Memory Protection) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-198268
Vulnerability Data
Tenda AC21 V16.03.08.16 is vulnerable to Buffer Overflow via the deviceId parameter in /goform/saveParentControlInfo.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The buffer overflow in the deviceId parameter of the publicly accessible /goform/saveParentControlInfo endpoint directly enables remote exploitation of a public-facing web application (T1190).
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation of input size/length for parameters such as deviceId before any copy operation, blocking the CWE-120 buffer overflow at the /goform/saveParentControlInfo endpoint.
Enforces memory protections (e.g., ASLR, non-executable stacks) that can prevent successful exploitation even if an oversized deviceId value reaches the vulnerable copy.
Mandates timely application of vendor patches that correct the unchecked buffer copy in saveParentControlInfo on the Tenda AC21 firmware.
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.
Secure development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.
Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.
Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.
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.
Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.
Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.
Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.
Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.
Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.