SB2021070206 - Multiple vulnerabilities in Mitsubishi Electric Air Conditioning System

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Incorrect Implementation of Authentication Algorithm (CVE-ID: CVE-2021-20593)

The vulnerability allows a remote attacker to gain elevated privileges on the target system.

The vulnerability exists due to incorrect implementation of the authentication algorithm. A remote authenticated attacker can impersonate an administrator and tamper with information (e.g., operation information and configuration of the air conditioning system).

2) XML External Entity injection (CVE-ID: CVE-2021-20595)

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to insufficient validation of user-supplied XML input. A remote attacker can pass a specially crafted XML code to the affected application and view contents of arbitrary files on the system or perform a denial of service (DoS) attack.

Successful exploitation of the vulnerability may allow an attacker to view contents of arbitrary file on the server or perform network scanning of internal and external infrastructure.

Remediation

Install update from vendor's website.

References

• https://ics-cert.us-cert.gov/advisories/icsa-21-182-04
• https://ics-cert.us-cert.gov/advisories/icsa-21-182-05