Overview

The vulnerability CVE-2025-20082 is a time-of-check time-of-use race condition found in the UEFI firmware SmiVariable driver. This vulnerability notably affects Intel(R) Server D50DNP and M50FCP boards, posing a significant threat to the security of these systems. It grants a privileged user the ability to escalate privileges via local access, which could potentially lead to system compromise or data leakage.

Vulnerability Summary

CVE ID: CVE-2025-20082
Severity: High (7.5 CVSS score)
Attack Vector: Local
Privileges Required: High
User Interaction: None
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

Intel(R) Server D50DNP | All versions prior to patch
Intel(R) Server M50FCP | All versions prior to patch

How the Exploit Works

The exploit takes advantage of a race condition in the UEFI firmware SmiVariable driver. A race condition occurs when the system’s behavior is dependent on the sequence or timing of uncontrollable events. In this case, a privileged user can exploit the time lapse between the check (time-of-check) and the use (time-of-use) of a variable. This allows the user to alter the variable during this time lapse, escalating their privileges and potentially compromising the system or leaking data.

Conceptual Example Code

The following pseudocode illustrates a conceptual example of how the vulnerability might be exploited:

// Attacker with high privileges executes code
function exploitRaceCondition() {
checkVariable(); // Time-of-check
delay(); // Time lapse
alterVariable(); // Time-of-use, altering the variable during the time lapse
}
exploitRaceCondition();

This code snippet represents the basic logic an attacker might follow to exploit this vulnerability, using their high privileges to check, delay, and then alter a variable.