CVE-2025-65212
Njhyst Hy511 Firmware ≤ 2.1
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2025-65212 is a critical-severity Reliance on Cookies without Validation and Integrity Checking (CWE-565) vulnerability in Njhyst Hy511 Firmware. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Web Session Cookie (T1550.004); ranked in the top 9% 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 AC-3 (Access Enforcement) and SC-23 (Session Authenticity) — 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-2025-65212, published on 2026-01-06, affects the NJHYST HY511 POE core software in versions before 2.1 and associated plugins before 0.1. The vulnerability arises from insufficient cookie verification, classified under CWE-565, with a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). This flaw enables an attacker to directly request and download the core configuration file without authenticating to the device management backend.
A remote attacker requires only network access to the device and can exploit this with low complexity and no privileges or user interaction. By downloading the configuration file, the attacker extracts the embedded username and self-decrypted MD5 password, enabling direct login to the backend and bypassing the front-end login page. This results in high-impact unauthorized access, potentially compromising confidentiality, integrity, and availability of the device.
Advisories and further details, including potential exploitation information, are provided in the following references: https://gist.github.com/a2148001284/bcdda75fc8718454f16a7b9259463719 and https://github.com/a2148001284/test1/blob/main/%E6%9C%AA%E6%8E%87%E6%9D%83%E8%AE%BF%E9%97%AE%E5%90%8E%E5%8F%B0%E6%BC%8F%E6%B4%9EEN.md.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-1016
Vulnerability Data
An issue was discovered in NJHYST HY511 POE core before 2.1 and plugins before 0.1. The vulnerability stems from the device's insufficient cookie verification, allowing an attacker to directly request the configuration file address and download the core configuration file…
more
without logging into the device management backend. By reading the corresponding username and self-decrypted MD5 password in the core configuration file, the attacker can directly log in to the backend, thereby bypassing the front-end backend login page.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Access Enforcement requires authorizations to be enforced by the system rather than by trusting client-supplied cookie values.
Session Authenticity directly requires protecting the integrity and authenticity of session tokens such as cookies, eliminating blind reliance on them.
Transmission Confidentiality and Integrity mandates cryptographic or equivalent protection for data in transit, which covers cookie values exchanged over HTTP.
Software, Firmware, and Information Integrity can detect unauthorized modification of cookie-based data after the fact via integrity verification.
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.
Cookies commonly carry identity assertions; requiring their protection, conveyance, and verification directly eliminates the weakness.
Strong authentication mechanisms reduce reliance on unvalidated cookies for identity and access decisions.
Cryptographic integrity for data-in-transit directly mitigates tampering of cookies sent over the network.
Enforcing access policy and least privilege limits damage from cookie misuse but does not address cookie validation itself.
Integrity protections for data-at-rest can apply to cookie stores but do not cover validation during use.
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.
Security testing can detect cookie-validation flaws but does not itself implement the required controls.
Application security requirements can mandate cookie validation, integrity protection, and server-side session handling.
Secure coding practices directly eliminate reliance on unvalidated cookies by requiring proper integrity checks and server-side verification.
Secure authentication mechanisms can enforce server-side validation and integrity checks that prevent reliance on untrusted cookies.