Rt Ac88u FirmwareOperating system · Asus

CVE-2020-29655

HIGH · 7.5 CVSS v3.1 Published 2020-12-09
Fix available
A fix is available. Upgrade to 3.1.0.108 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An injection vulnerability exists in RT-AC88U Download Master before 3.1.0.108. Accessing Main_Login.asp?flag=1&productname=FOOBAR&url=/downloadmaster/task.asp will redirect to the login site, which will show the value of the parameter productname within the title. An attacker might be able to influence the appearance of the login page, aka text injection.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A reflected text injection vulnerability in ASUS RT-AC88U Download Master allows the productname URL parameter to be directly reflected into the login page's HTML title without sanitization. An attacker can craft a malicious URL with arbitrary text in the productname parameter to influence the login page's appearance.

MitigationUpdate Download Master to version 3.1.0.108 or later, which contains proper input validation for the productname parameter. If immediate patching is not feasible, restrict network access to the Download Master interface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Rt Ac88u FirmwareOperating system
Affected:< 3.1.0.108

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device model
    Access the router admin interface or check the device label to verify the model is ASUS RT-AC88U
    Affected if Device is not an ASUS RT-AC88U (not affected)
  2. Check Download Master version
    Navigate to the Download Master page in the router firmware (typically under USB application or Download Master settings) and locate the firmware version number
    Affected if Version is 3.1.0.108 or higher (not affected); version is below 3.1.0.108 (potentially affected)
  3. Verify Download Master interface is accessible
    Attempt to access the Download Master web interface over HTTP/HTTPS on the local network (commonly on port 8081 or as a subsection of the main router interface)
    Affected if Download Master interface is not exposed or accessible (not affected)
  4. Test for reflected parameter injection
    Craft a URL to the Download Master login page with a test productname parameter value, for example: http://<router-ip>/downloadmaster?productname=TESTINJECTION and examine if the submitted value appears unsanitized in the page title or HTML
    Affected if The productname parameter value is reflected directly in the HTML without encoding or sanitization (vulnerable)

You are affected if your device is an ASUS RT-AC88U running Download Master firmware version below 3.1.0.108 AND the Download Master web interface is accessible on your network.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 3.1.0.108 or later
Fixed in 3.1.0.108
Interim mitigation

Update Download Master to version 3.1.0.108 or later, which contains proper input validation for the productname parameter. If immediate patching is not feasible, restrict network access to the Download Master interface.

Fix this in Rt Ac88u Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-29655 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data