An issue was discovered on Brother MFC-J491DW C1806180757 devices. The printer's web-interface password hash can be retrieved without authentication, because the response header of any failed login attempt returns an incomplete authorization cookie. The value of the authorization cookie is the MD5 hash of the password in hexadecimal. An attacker can easily derive the true MD5 hash from this, and use offline cracking attacks to obtain administrative access to the device.

Null pointer dereference vulnerability exists in multiple vendors MFPs and printers which implement Debut web server 1.2 or 1.3. Processing a specially crafted request may lead an affected product to a denial-of-service (DoS) condition. As for the affected products/models/versions, see the detailed information provided by each vendor.

Some Brother printers (such as the HL-L8360CDW v1.20) were affected by different information disclosure vulnerabilities that provided sensitive information to an unauthenticated user who visits a specific URL.

Some Brother printers (such as the HL-L8360CDW v1.20) were affected by a stack buffer overflow vulnerability as the web server did not parse the cookie value properly. This would allow an attacker to execute arbitrary code on the device.

Some Brother printers (such as the HL-L8360CDW v1.20) were affected by a heap buffer overflow vulnerability as the IPP service did not parse attribute names properly. This would allow an attacker to execute arbitrary code on the device.