ASUS RT-AX55
Security Evaluation
1. Device Security
2. System Security
3. User Authentication
Technical Specifications
Evidence review addendum — 2026-10-24. Public-document review; ratings with evidence gaps remain provisional.
This addendum supersedes earlier inconsistent wording on the same fields. It is based on public documents and the saved website snapshot; no installed device was tested. Historical research below remains historical evidence. Unverified flash protection and interface-specific controls are not verified device facts.
Documented basic information
- 电源: AC input 110–240 V 50–60 Hz; DC output 12 V, max. 1 A Source
Revised security evidence notes
- 闪存存储加密: At-rest encryption of configuration and credentials on 3.0.0.4.386_53370 is unverified. Published older-firmware extraction is indirect evidence only. Source Source
- 防暴力破解: ASUS documents CAPTCHA after repeated errors and a warning after five incorrect logins. RT-AX55 build-specific applicability and duration have not been verified. Source
- 事件日志: Network logs are documented. Historical build 52332 login-event coverage was disputed; 53370 changes logging data handling but does not specify administrator access-event coverage. Current-build access logging remains unverified. Source Source Source
- 密码规则: The model quick-start guide creates a router login password. Firmware 3.0.0.4.386_53244 introduced a 10-character minimum; ASUS recommends a factory reset to apply enhancements. Mixed-character complexity enforcement is not established. Source Source
- 已知硬件篡改: External power, reset and Ethernet interfaces permit interruption or reset with physical access; internal changes require enclosure access. Rare is an assessor inference, not a measured incident frequency. Source Source
- 既往攻击: A real ASUS router compromise campaign was reported. Related historical exploitation was reproduced on RT-AX55; the campaign-wide device count is not a model-specific infection count. Rare is a qualitative mapping. Source Source
- 与其他系统认证: Administration uses credentials; ordinary DHCP, DNS and discovery paths do not establish universal peer authentication. Partial is a service-scope assessment, not a claim of mutual authentication on every interface. Source
- 账号管理: Router administrator credential changes are documented. Creation and deletion of lower-privilege local management accounts have not been established; an ASUS cloud account alone does not substantiate Full local account management. Source
- 通信加密: Conditional supported-configuration assessment: HTTPS administration and WPA3-Personal or WPA2-AES; disable plaintext remote administration and Telnet. Other traffic and actual enabled settings were not inspected. Source Source
- 已知漏洞: Published historical RT-AX55 management vulnerabilities exist; affected builds and patched later releases must be distinguished. Rare is a provisional qualitative mapping pending a common observation window, not measured prevalence. Source Source Source
Scoring status
Existing selected scores are a saved comparison baseline, not newly validated final scores. Recheck version, region and assessment path before updating options. Recalculate CATS/GRAS and synchronize this section after all selected options are settled. Do not infer a secure or insecure flash state from a downloadable firmware image or encrypted data volumes.
Assessment reviewed 2026-10-22. Documented capability assessment with explicitly labelled assessor inferences; no individual installed device was tested.
Assessment scope
Stock RT-AX55. Latest release visible in the reviewed model page: 3.0.0.4.386_53370, 2026-09-04. No physical device or installed configuration was inspected.
The rubric has no numerical frequency thresholds. Qualitative mappings are explained in each comment; an inferred risk rating is not a measured incident rate. Configuration benefits apply only when the specified controls are enabled.
The date is the scheduled Japan retail release announced by ASUS Japan, 22 January 2021, not a worldwide first-launch claim. ASUS Japan launch announcement
Previous calculation
The old submitted score arrays have been withdrawn because they differ from the saved structured-field snapshot. Recalculate from the final selected fields after pending scoring decisions.
Evidence and inference notes
- Known hardware tampering: ASSESSOR INFERENCE: Rare denotes a local-access barrier. Reset, power and Ethernet controls permit configuration changes or service interruption by a physically present person; no tamper-proof certification or measured incident frequency is claimed. RT-AX55 user guide E21014 ASUS setup and reset FAQ
- Known vulnerabilities: ASSESSOR INFERENCE: Very common reflects recurring independent published management weaknesses and command injection, not measured prevalence. Historical affected firmware and patched current releases are distinguished below. ASUS security advisories GreyNoise original RT-AX55 research Current TWCERT/CC CVE-2023-39238 notice
- Prior attacks: ASSESSOR INFERENCE: Rare represents the verified ASUS campaign relevant to this model. GreyNoise observed real compromised ASUS routers and reproduced the related path on RT-AX55 3.0.0.4.386.51598. Its fleet total is not an RT-AX55 infection count. GreyNoise ASUS campaign GreyNoise original RT-AX55 research
- Updatability: Several official firmware releases were published during 2026. RT-AX55 firmware
- Authentication with other systems: Partial describes the service set: administration requires credentials, while DHCP/DNS and network discovery do not universally authenticate peers. This does not claim mutual authentication for every attached system. RT-AX55 user guide E21014
- Communications: Conditional management/Wi-Fi scope: use HTTPS-only administration and WPA3-Personal or WPA2-AES; disable Telnet and plaintext remote administration. These supported settings justify the protected-channel rating. HTTP mode, legacy Wi-Fi and discovery traffic are excluded; this is not an inspected installation. RT-AX55 specifications RT-AX55 user guide E21014
- Storage: ASSESSOR INFERENCE, firmware-code flash scope: published stock RT-AX55 firmware research extracts an ordinary filesystem and analyses executable/NVRAM use. No encryption is a limited firmware-code assessment, not proof that every credential is plaintext. The directly analysed historical build is 3.0.0.4.386.51598. Original RT-AX55 stock firmware analysis GreyNoise original RT-AX55 research
- Account management: An administrator credential is documented; full local role management was not demonstrated. RT-AX55 user guide E21014
- Authentication: Local management uses username/password; local MFA was not established. RT-AX55 user guide E21014
- Brute-force protection: ASSESSOR INFERENCE: Basic denotes the configurable login CAPTCHA, which impedes automated guessing. The control is documented; no universal model/build-specific attempt count or lockout duration is claimed. ASUS login CAPTCHA control RT-AX55 firmware
- Event logging: System Log records network activity; exhaustive administrator-access auditing is not established. RT-AX55 user guide E21014
- Passwords: Setup creates a router login/password. Firmware 3.0.0.4.386_53244 introduced a ten-character minimum, recommending reset to apply it. This maps to the setup-password bucket; length alone does not prove enforced mixed-character complexity. RT-AX55 quick setup guide RT-AX55 firmware
Historical vulnerabilities and remediation
CVE-2023-39780: Authenticated command injection
- Affected scope: RT-AX55 3.0.0.4.386.51598 explicitly documented by original researchers; wider range unverified.
- Preconditions: Reachable management service and an authenticated session; initial-access flaws are separate.
- Impact: System commands and persistent unauthorized configuration.
- Remediation: Vendor fixes reported; first fully fixed build across related paths not established here. Use current official firmware; existing backdoor settings require separate review.
- Severity: Numeric score not independently verified; omitted.
CVE-2023-39238: Authenticated format-string flaw
- Affected scope: Current TWCERT/CC notice lists RT-AX55 3.0.0.4.386_50460. Do not infer all earlier builds.
- Preconditions: Remote attacker with administrator privileges, current CNA notice.
- Impact: Code execution or service disruption.
- Remediation: RT-AX55 3.0.0.4.386_51948.
- Severity: CVSS 3.1: 7.2; AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H, current TWCERT/CC.