Wa300 FirmwareOperating system · Totolink

CVE-2026-4497

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Public exploit 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
A vulnerability was determined in Totolink WA300 5.2cu.7112_B20190227. Affected by this issue is the function recvUpgradeNewFw of the file /cgi-bin/cstecgi.cgi. This manipulation causes os command injection. Remote exploitation of the attack is possible. The exploit has been publicly disclosed and may be utilized.

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 · high confidence

OS command injection vulnerability in the recvUpgradeNewFw function of /cgi-bin/cstecgi.cgi on Totolink WA300 router firmware 5.2cu.7112_B20190227. The function handling firmware upgrades fails to sanitize input before passing it to system shell commands, allowing remote attackers to execute arbitrary OS commands.

MitigationApply vendor-supplied patched firmware; if unavailable, disable remote web management interfaces or isolate the device behind a firewall to reduce attack surface.

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
Wa300 FirmwareOperating system
Affected:= 5.2cu.7112_b20190227

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
High
Integrity
High
Availability
High

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

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. Identify installed firmware version
    Access the router web administration interface and navigate to System Status or Firmware version page, or use telnet/SSH to run 'cat /proc/version' or '固件版本' related command
    Affected if Firmware version matches exactly 5.2cu.7112_b20190227
  2. Verify vulnerable CGI binary exists
    Check if /cgi-bin/cstecgi.cgi exists on the device by accessing it via HTTP/HTTPS or using telnet/SSH to list the /cgi-bin/ directory
    Affected if The file /cgi-bin/cstecgi.cgi is present on the device
  3. Confirm firmware upgrade functionality is accessible
    Attempt to access the firmware upgrade web interface or check if the recvUpgradeNewFw function is exposed via the CGI endpoint
    Affected if The firmware upgrade function (recvUpgradeNewFw) is accessible via the web interface or CGI binary
  4. Check if remote web management is enabled
    Log into router admin panel and verify Status or Network settings for remote management options, or test connectivity to ports 80/443 from external IP
    Affected if Remote web management (HTTP/HTTPS from WAN) is enabled and accessible

Device is affected if it runs firmware version 5.2cu.7112_b20190227 AND has the /cgi-bin/cstecgi.cgi binary with the firmware upgrade function accessible, especially if remote web management is enabled.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor-supplied patched firmware; if unavailable, disable remote web management interfaces or isolate the device behind a firewall to reduce attack surface.

Fix this in Wa300 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-4497 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2026-4497 in production — separate from our analysis above.

No notes yet

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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
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