Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2025-14656 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda Ac20 Firmware. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 49% of CVEs by exploit likelihood; 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 SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — 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-2025-14656 is a buffer overflow vulnerability (CWE-119, CWE-120) affecting Tenda AC20 router firmware version 16.03.08.12. The flaw exists in the httpd function of the /goform/openSchedWifi file, where manipulation of the schedStartTime and schedEndTime arguments triggers the overflow. Published on 2025-12-14, it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high severity.
The vulnerability enables remote exploitation over the network with low attack complexity, requiring only low privileges such as an authenticated user account. No user interaction is needed, and successful attacks can achieve high impacts on confidentiality, integrity, and availability, potentially leading to arbitrary code execution or full device compromise.
VulDB advisories (ctiid.336389, id.336389, submit.712917) document the issue, while a proof-of-concept exploit is publicly available on GitHub (https://github.com/Madgeaaaaa/MY_VULN_2/blob/main/Tenda/VULN14/AC20_openSchedWifi.md). The Tenda website (https://www.tenda.com.cn/) is referenced, but no specific patches or mitigations are detailed in the provided information. The public exploit availability increases the risk of real-world attacks.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-203297
Vulnerability Data
A weakness has been identified in Tenda AC20 16.03.08.12. This affects the function httpd of the file /goform/openSchedWifi. Executing a manipulation of the argument schedStartTime/schedEndTime can lead to buffer overflow. The attack may be performed from remote. The exploit has…
more
been made available to the public and could be used for attacks.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V17.3.2V5.2.1
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and analysis can find missing size checks before deployment.
Input validation directly enforces size checks before buffer copies.
Secure engineering principles require memory-safe design and coding that structurally avoids buffer-boundary violations.
Memory protection restricts exploitation impact of buffer overflows without eliminating the underlying coding flaw.
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 SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.
Vulnerability scanning and code analysis directly surface buffer-boundary flaws.
Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.
Developer training on secure coding reduces introduction of memory-buffer errors.
Patching replaces vulnerable code containing buffer-boundary defects.
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 catches out-of-bounds accesses before release, covering most instances of the weakness.
Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.
Application security requirements can specify memory-safety rules, but do not prescribe implementation details.
Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.