Two more supply chain security flaws have been disclosed in AMI MegaRAC Baseboard Management Controller (BMC) software, nearly two months after three security vulnerabilities were brought to light in the same product.

Firmware security firm Eclypsium said the two shortcomings were held back until now to provide AMI additional time to engineer appropriate mitigations.

The issues, collectively tracked as BMC&C, could act as springboard for cyber attacks, enabling threat actors to obtain remote code execution and unauthorized device access with superuser permissions.

The two new flaws in question are as follows -

• CVE-2022-26872 (CVSS score: 8.3) - ​​Password reset interception via API
• CVE-2022-40258 (CVSS score: 5.3) - Weak password hashes for Redfish and API

Specifically, MegaRAC has been found to use the MD5 hashing algorithm with a global salt for older devices, or SHA-512 with per user salts on newer appliances, potentially allowing a threat actor to crack the passwords.

CVE-2022-26872, on the other hand, leverages an HTTP API to dupe a user into initiating a password reset by means of a social engineering attack, and set a password of the adversary's choice.

CVE-2022-26872 and CVE-2022-40258 add to three other vulnerabilities disclosed in December, including CVE-2022-40259 (CVSS score: 9.9), CVE-2022-40242 (CVSS score: 8.3), and CVE-2022-2827 (CVSS score: 7.5).

It's worth pointing out that the weaknesses are exploitable only in scenarios where the BMCs are exposed to the internet or in cases where the threat actor has already gained initial access into a data center or administrative network by other methods.

The blast radius of BMC&C is currently unknown, but Eclypsium said it's working with AMI and other parties to determine the scope of impacted products and services.

Gigabyte, Hewlett Packard Enterprise, Intel, and Lenovo have all released updates to address the security defects in their devices. NVIDIA is expected to ship a fix in May 2023.

"The impact of exploiting these vulnerabilities include remote control of compromised servers, remote deployment of malware, ransomware and firmware implants, and server physical damage (bricking)," Eclypsium noted.