CVE-2024-51978 Scanner

Brother Printers are widely used in both consumer and business environments for printing, scanning, and faxing documents. These printers are often integrated into networks, allowing users to print documents remotely and manage the printer settings through a web interface. Brother Printers offer various features such as wireless printing, mobile printing, and cloud connectivity, making them versatile tools in modern office setups. The administrative interface of these printers allows for configuration and management, which is essential for ensuring that the devices are running optimally and securely. With network connectivity, administrators can manage printer settings remotely, which can save time and resources compared to handling these settings directly on the device. Although they are user-friendly and functional, it's crucial that the security settings on Brother Printers are properly configured to prevent unauthorized access.

The Authentication Bypass vulnerability in Brother Printers allows an attacker to gain unauthorized access to the printer by exploiting the default administrator password. This issue arises when the printer's serial number, which can be obtained through simple network queries, is used to generate the default password of the administrator account. The vulnerability is particularly dangerous because it allows remote attackers to take control of the printer without any previous authentication, leading to unauthorized usage and potential misuse. This bypass can be executed using information obtained via unauthenticated HTTP, HTTPS, IPP, SNMP, or PJL requests. This problem highlights the importance of changing default credentials on network devices to prevent unauthorized access.

The technical details of the vulnerability involve manipulating the printer's default administrative password generation process. By obtaining the printer's serial number and using it alongside a known script or algorithm, an attacker can recreate the default administrative password. The process involves a series of character and encoding manipulations that leverage the serial number as an input. This can be accomplished by accessing specific endpoint URLs that reveal the serial number. Additionally, the method requires an understanding of the device's password generation mechanism, which relies heavily on the interaction between JavaScript codes and hashed passwords. Malicious users can use this method to establish a session and gain access through the administrative interface using the default password.

Exploiting the Authentication Bypass vulnerability can lead to several detrimental effects. An unauthorized user could change printer settings, access or alter stored documents, or even use the device for malicious activities such as launching network attacks or disseminating spam. The attacker could potentially disable the printer or alter its configurations to disrupt business operations or steal sensitive corporate data. In some cases, the printer could be used as a proxy for further attacks on the internal network, increasing the risk of significant information compromise. This vulnerability, if exploited, represents a critical security hole that could offer attackers a foothold within a network, potentially compromising other connected devices.

REFERENCES

• https://www.rapid7.com/blog/post/multiple-brother-devices-multiple-vulnerabilities-fixed
• https://github.com/sfewer-r7/BrotherVulnerabilities
• https://support.brother.com/g/b/faqend.aspx?c=eu_ot&lang=en&prod=group2&faqid=faq00100846_000