Active exploitation of all of the identified problems cannot be detected by firmware integrity monitoring systems, as per Firmware Insyde Software's InsydeH2O and HP Unified Extensible Firmware Interface (UEFI), which discovered the vulnerabilities. As previously stated, secure remote health attestation systems are unable to detect compromised systems due to technical limitations.
The high-severity vulnerabilities are identified as CVE-2022-24415, CVE-2022-24416, CVE-2022-24419, CVE-2022-24420, and CVE-2022-24421 on the CVSS scoring system.
All of the weaknesses are related to poor input validation vulnerabilities in the firmware's System Management Mode (SMM), permitting a local privileged attacker to execute arbitrary code via the management system interrupt (SMI). System Management Mode in x86 microcontrollers is a special-purpose CPU mode for performing system-wide functions like power efficiency, hardware and system control, temperature monitoring, and other exclusive manufacturer-developed code.
A non-maskable interrupt (SMI) is activated at runtime whenever one of these tasks is requested, and SMM code installed by the BIOS is executed. The method is ripe for misuse because SMM code runs at the greatest privilege level and is transparent to the underlying operating system, making it ideal for implanting persistent firmware. A variety of Dell products are affected, including the Alienware, Inspiron, Vostro, and Edge Gateway 3000 Series, with the Texas-based PC company advising customers to replace their BIOS as soon as possible.
"The ongoing identification of these vulnerabilities demonstrates what we call repeatable failures' around input cleanliness or, in general, insecure coding habits," according to Binarly researchers. "These errors are directly related to the codebase's complexity or support for legacy components which receive less security attention but are nevertheless frequently used in the field. In many cases, the same vulnerability can be addressed numerous times, yet the attack surface's complexity still leaves open gaps for malicious exploitation."
Dell SupportAssist is a program which manages support functions such as troubleshooting and recovery on Windows-based Dell workstations. The BIOSConnect feature can be used to restore a corrupted operating system as well as upgrade firmware.
The functionality does this by connecting to Dell's cloud infrastructure and pulling required code to a user's device.
