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Description

WDR201A WiFi Extender (HW V2.1, FW LFMZX28040922V1.02) contains an OS command injection vulnerability in the firewall.cgi binary across five request handlers that apply insufficient input validation. Attackers can inject arbitrary shell commands through vulnerable parameters like websURLFilter, websHostFilter, portForward, singlePortForward, and ipportFilter using subshell syntax or unfiltered parameters, with payloads persisting in NVRAM and re-executing on every subsequent firewall.cgi request.

PUBLISHED Reserved 2026-04-22 | Published 2026-05-04 | Updated 2026-05-08 | Assigner VulnCheck




CRITICAL: 9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Problem types

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Product status

Default status
unaffected

Any version
affected

Credits

Matteo Strada finder

References

mstreet97.github.io/...aching_the_Machine_Where_to_Look.html technical-description exploit

www.made-in-china.com/showroom/yeapook/ product

www.vulncheck.com/...r-os-command-injection-via-firewall-cgi third-party-advisory

cve.org (CVE-2026-41926)

nvd.nist.gov (CVE-2026-41926)

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