CVE-2021-3017: The web interface on Intelbras WIN 300 and WRN 342 devices through 2021-01-04 allows remote attackers to discover credentials by reading the…

PriorityP271high7.5CVSS 3.1

AVNACLPRNUINSUCHINAN

EXPLOIT

EPSS

63.02%

99.1th percentile

The web interface on Intelbras WIN 300 and WRN 342 devices through 2021-01-04 allows remote attackers to discover credentials by reading the def_wirelesspassword line in the HTML source code.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
intelbras	win_300_firmware	<= 2021-01-04	—
intelbras	wrn_342_firmware	<= 2021-01-04	—

Detection & IOCsextracted from sources · hover to see the quote

url/index.asp

otherdef_wirelesspassword =

yara

regex: 'def_wirelesspassword = "([A-Za-z0-9=]+)";'

→Send an unauthenticated HTTP GET request to /index.asp on the target device. A vulnerable Intelbras WIN 300 or WRN 342 device will return HTTP 200 with both 'def_wirelesspassword =' and 'Roteador Wireless' present in the response body, indicating credentials are exposed in the HTML source.
→Extract the plaintext wireless password from the HTML body using the regex pattern: def_wirelesspassword = "([A-Za-z0-9=]+)"; — credentials are embedded directly in the page source without authentication. ↗

·The vulnerability affects Intelbras WIN 300 and WRN 342 devices through firmware dated 2021-01-04 only. Devices on newer firmware may not be vulnerable. ↗
·Only a single HTTP request is required (max-request: 1), making this trivially exploitable at scale with no authentication, no special headers, and no prior knowledge of credentials.

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:P/I:N/A:N

vendor_redhat5.5MEDIUM

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