IRONSMITHINTEL
CRITICALCVSS9.8
|
Actively Exploited
|CISA KEV|CVE-2021-32030|Auth: none — unauthenticated|Reboot: required|Manual only

ASUS Routers Improper Authentication Vulnerability (CVE-2021-32030)

ASUS Lyra Mini and ASUS GT-AC2900 devices contain an improper authentication vulnerability that allows an attacker to gain unauthorized access to the administrative interface. The impacted products could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization.

Published May 6, 2021 · Updated May 17, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2025-06-23 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Improper Authentication (CWE-287) vulnerability in 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. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

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Phishing link

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Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

IT Security
Running lyra mini firmware: v < 3.0.0.4.384.46630; gt-ac2900 firmware: v < 3.0.0.4.386.42643
Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0010.md

How to patch

Manual remediation steps

1
Identify affected hosts: query inventory for general installs in scope.
2
Apply the vendor security update referenced in CVE-2021-32030's advisory. No specific KB/version is encoded yet — consult the linked MSRC/vendor URL.
3
Verify the fix per the vendor's published verification steps.
4
Document the remediation in your change ticket and re-scan with your vulnerability scanner to confirm closure.
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