SB2021042705 - Multiple vulnerabilities in Buffalo routers

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Path traversal (CVE-ID: CVE-2021-20090)

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in the web interfaces. A remote attacker can send a specially crafted HTTP request and bypass authentication.

Note, the vulnerability is being exploited in-the-wild by the Mirai botnet in August 2021.

2) Code Injection (CVE-ID: CVE-2021-20091)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in the web interfaces. A remote authenticated attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

3) Improper access control (CVE-ID: CVE-2021-20092)

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions in the web interfaces. A remote attacker can bypass implemented security restrictions and gain unauthorized access to sensitive information on the system.

Remediation

Cybersecurity Help is not aware of any official remediation provided by the vendor.

References

• https://www.tenable.com/security/research/tra-2021-13
• https://medium.com/tenable-techblog/bypassing-authentication-on-arcadyan-routers-with-cve-2021-20090-and-rooting-some-buffalo-ea1dd30980c2