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CRITICAL · CVSS 9.8 CISA Known Exploited Vulnerability

CVE-2021-32030

ASUS Routers Improper Authentication Vulnerability

ASUS Routers

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 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.

CVSS
9.8
CRITICAL
EPSS
99.4%
30-day exploitation
Ransomware groups
0
recorded exploiting
Published
6 May 2021
CWE-287

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 2 June 2025. US federal agencies were required to remediate it by 23 June 2025.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 99.4%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Frequently asked questions

Is CVE-2021-32030 being exploited by ransomware groups?

No ransomware group in this database is currently recorded as exploiting CVE-2021-32030.

What does CVE-2021-32030 affect?

CVE-2021-32030 affects ASUS Routers. 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 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.

How severe is CVE-2021-32030?

CVE-2021-32030 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 99.4%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 23 June 2025.

How should organisations respond to CVE-2021-32030?

Apply the vendor patch for ASUS Routers as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.