Additional Supply Chain Vulnerabilities Uncovered in AMI MegaRAC BMC Software

Feb 01, 2023Ravie LakshmananServer and Cloud Security

Two more supply chain security flaws have been disclosed in AMI
MegaRAC Baseboard Management Controller (BMC) software, nearly two
months after three security vulnerabilities^[1] were brought to light in
the same product.

Firmware security firm Eclypsium said^[2]
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^[3] (CVSS score: 8.3) –
  ​​Password reset interception via API
• CVE-2022-40258^[4] (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^[5] 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^[6]
(CVSS score: 9.9), CVE-2022-40242^[7]
(CVSS score: 8.3), and CVE-2022-2827^[8]
(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^[9]
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.