CVE-2021-3017

What it actually does

The flaw exposes wireless credentials in the HTML source of the affected device web interface. A remote, unauthenticated attacker who can reach the management interface can retrieve the value associated with the `def_wirelesspassword` field without needing valid login credentials. The primary impact is loss of confidentiality: the attacker can learn Wi-Fi or device-related secrets and potentially use them to access the local network or pivot to other systems. The provided metadata also lists a fixed source revision for `kirilkirkov/ecommerce-codeigniter-bootstrap`; however, the CVE description itself is for Intelbras WIN 300 and WRN 342 device web interfaces, so asset owners should verify product applicability before applying package-specific remediation guidance.

Why it matters to the business

Organizations using exposed affected devices risk unauthorized network access if attackers recover wireless credentials from the management interface. This can lead to rogue device connections, interception of internal traffic, access to systems that rely on Wi-Fi segmentation, and increased incident response costs. Although this CVE is not listed in CISA KEV and is not marked as ransomware-associated, it has weaponized exploit maturity and a high EPSS score of 0.63023, indicating meaningful likelihood of exploitation in the wild, especially where device administration pages are reachable from untrusted networks.

How an attack unfolds

An attacker first scans for reachable Intelbras WIN 300 or WRN 342 web management interfaces. Because the vulnerability requires no authentication, the attacker sends an HTTP request to the affected web interface page and reviews the returned HTML source. If the response contains the `def_wirelesspassword` line, the attacker extracts the exposed password value. The attacker can then attempt to join the wireless network, reuse the credential against related services if password reuse exists, or use the recovered access as a foothold for internal reconnaissance and lateral movement. Exploitation is low-complexity and can be automated at internet scale when management interfaces are exposed.

How to fix it

Restrict access to device management interfaces immediately: block internet exposure, allow administration only from trusted management networks, and disable remote administration where possible. Upgrade affected firmware or replace devices if the vendor no longer provides supported firmware. After patching, rotate any exposed wireless and administrative credentials because they should be considered compromised if the interface was reachable by untrusted users. Review Wi-Fi security configuration and prefer WPA2/WPA3 with strong unique passphrases. If using the separately supplied package metadata, update `kirilkirkov/ecommerce-codeigniter-bootstrap` to commit `7c3c32d6526268b1c78d6d5741361e79292e9c22` or later, but validate applicability because this package does not match the CVE device description.

How to confirm the fix worked

Confirm exposure by testing only authorized assets: request the device web interface while unauthenticated and verify that the HTML source no longer contains `def_wirelesspassword` or any plaintext credential value. Validate that the management interface is not reachable from the internet or guest/untrusted networks. Confirm firmware or software inventory shows a fixed or vendor-supported version. After credential rotation, verify that old wireless credentials no longer permit association. If using network scanning, flag any affected model with unauthenticated management access as still exposed until both patching and access restrictions are confirmed.

Typical attack path

1. Identify internet-facing or otherwise reachable affected Intelbras WIN 300 or WRN 342 management interfaces.
2. Send unauthenticated HTTP requests to the device web interface.
3. Inspect the returned HTML source for the `def_wirelesspassword` field.
4. Extract the exposed wireless credential.
5. Use the credential to connect to the wireless network or attempt credential reuse against other services.
6. Perform internal reconnaissance, traffic interception, or lateral movement from the newly gained network position.

How to detect it

Look for evidence that unauthenticated users accessed affected management interfaces before remediation. Useful sources include router web management logs if available, upstream firewall logs, reverse proxy logs, NAT logs, NetFlow, wireless controller logs, DHCP lease history, RADIUS authentication logs, and endpoint/network detection telemetry. Search for HTTP requests to affected device management interfaces from external, guest, or otherwise unexpected source addresses. If full packet capture, proxy response logging, or web content inspection is available, search returned HTML for `def_wirelesspassword`, which is the key artifact of credential exposure. Because many small routers keep minimal logs, absence of device logs should not be treated as proof of no exploitation. Also investigate unknown wireless client associations, new DHCP leases, repeated failed or successful joins using the old SSID password, and internal scanning activity shortly after suspicious access to the management interface.

• def_wirelesspassword
• wirelesspassword
• GET / HTTP/1.1
• GET /index.html
• GET /login.html
• Intelbras WIN 300
• Intelbras WRN 342
• 7c3c32d6526268b1c78d6d5741361e79292e9c22

What your security team should do

• Prioritize identifying Intelbras WIN 300 and WRN 342 devices, especially any with management interfaces reachable from the internet or untrusted networks.
• Immediately restrict management access with firewall rules, ACLs, VPN-only administration, or physical/local-only management.
• Patch or replace affected devices; if relying on supplied package metadata, verify whether `kirilkirkov/ecommerce-codeigniter-bootstrap` is actually in scope before upgrading to commit `7c3c32d6526268b1c78d6d5741361e79292e9c22` or later.
• Rotate wireless and administrative credentials for any device that may have been exposed.
• Review wireless association logs and DHCP leases for unknown clients that appeared before remediation.
• Add detection content for requests/responses containing `def_wirelesspassword` and for unauthenticated access to router management pages from unusual sources.
• Treat exposed credentials as compromised even if there is no definitive exploitation evidence, because successful exploitation may leave limited logs on embedded devices.