Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2021-32030 is a critical-severity Improper Authentication (CWE-287) vulnerability in Asus Lyra Mini Firmware. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 0.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
The vulnerability is an authentication bypass flaw (CWE-287) affecting the administrator web interface on ASUS GT-AC2900 routers running firmware prior to 3.0.0.4.386.42643 and Lyra Mini devices prior to 3.0.0.4_384_46630. It stems from improper handling in router/httpd/httpd.c (handle_request) and web_hook.o (auth_check), where an attacker-supplied null byte ('\0') can match the device's default credential value, granting unauthenticated access to administrative functions. All end-of-life Lyra Mini versions are also impacted.
An unauthenticated remote attacker can exploit the flaw over the network by sending a crafted request to the web interface, achieving full unauthorized access to the administrator application. With a CVSS score of 9.8, the issue requires no privileges or user interaction and can result in complete compromise of confidentiality, integrity, and availability of the device.
Advisories from ASUS and Atredis Partners recommend applying the fixed firmware versions listed on the vendor support pages for GT-AC2900 and Lyra Mini. Consumers can further mitigate exposure by disabling remote WAN access to the administrative interface, particularly on unsupported EOL devices where patches are unavailable.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-18896
Vulnerability Data
The administrator application on ASUS GT-AC2900 devices before 3.0.0.4.386.42643 and Lyra Mini before 3.0.0.4_384_46630 allows authentication bypass when processing remote input from an unauthenticated user, leading to unauthorized access to the administrator interface. This relates to handle_request in router/httpd/httpd.c and…
more
auth_check in web_hook.o. An attacker-supplied value of '\0' matches the device's default value of '\0' in some situations. Note: All versions of Lyra Mini and earlier which are unsupported (End-of-Life, EOL) are also affected by this vulnerability, Consumers can mitigate this vulnerability by disabling the remote access features from WAN.
- CWE(s)
- KEV Date Added
- 02 June 2025
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Detects unauthorized successful logons resulting from improper authentication implementations.
Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.
Security awareness training instructs users on secure authentication practices and avoiding credential compromise.
Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.
Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.
Session content review can reveal authentication bypasses or failures in session establishment.
Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.
Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.
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.
Mandating segregated approval and oversight for non-human identities reduces the chance that weak or orphaned credentials can be exploited for unauthorized authentication.
A.5.17 directly mandates generation of non-guessable unique secrets, secure transmission, immediate change of defaults/temporary creds, strong password enforcement, no-reuse, and compromise response, which stops most improper-authentication exploits at source; the bounded remainder is non-password authentication methods and sufficiency-of-proof cases (e.g. IA-2/IA-5 enhancements) left to other controls.
Security requirements specified early and verified through testing drive the consistent implementation of authentication mechanisms, decreasing the likelihood that authentication steps are omitted or incorrectly applied.
A.8.26 explicitly requires identifying and addressing authentication-related requirements (including level of trust in identity via 8.5 and 5.17) as part of application development or acquisition, which prevents a slice of CWE-287 but leaves the dominant sufficiency-of-proof aspects (IA-2/IA-5) and many implementation defects untouched.
A.8.27 mandates security-by-design principles (least privilege, default-deny, never-trust/always-verify, MFA, end-to-end encryption of requests, distrust-external-input, secure session control, and explicit authentication/authorization in every layer), which directly stops most improper-authentication flaws from being exploitable; the bounded remainder is insufficient-proof cases that live only in the strength or correctness of the credential itself (IA-5/IA-2 territory).
A.8.5 directly mandates appropriate-strength authentication techniques, MFA for critical systems, protected log-on procedures, brute-force resistance, no cleartext passwords/transmission, and session controls that stop exploitation of insufficient proof of identity; the bounded remainder is cases where the chosen technique itself is flawed or insufficiently implemented (e.g. weak biometrics without fallback).
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.