Learn about CVE-2021-21539, a TOCTOU race condition flaw in Dell EMC iDRAC9 prior to version 4.40.00.00. Understand the impact, technical details, and mitigation steps for this Medium-severity vulnerability.
This article provides details about CVE-2021-21539, a Time-of-check Time-of-use (TOCTOU) race condition vulnerability in Dell EMC iDRAC9 versions prior to 4.40.00.00. Learn about the impact, technical details, and mitigation steps associated with this CVE.
Understanding CVE-2021-21539
CVE-2021-21539 is a vulnerability in Dell's Integrated Dell Remote Access Controller (iDRAC) that allows a remote authenticated attacker to potentially gain elevated privileges through a TOCTOU race condition.
What is CVE-2021-21539?
Dell EMC iDRAC9 versions before 4.40.00.00 have a TOCTOU race condition flaw. An attacker could exploit this vulnerability to escalate privileges while a higher-privileged user is accessing iDRAC via the web interface.
The Impact of CVE-2021-21539
With a CVSS base score of 5.9 (Medium severity), this vulnerability poses a threat to the integrity of affected systems. An attacker could execute privileged actions when simultaneous high-privileged access occurs.
Technical Details of CVE-2021-21539
Understand the vulnerability, affected systems, and the exploitation mechanism.
Vulnerability Description
The TOCTOU race condition in iDRAC9 versions < 4.40.00.00 allows remote authenticated attackers to elevate privileges by exploiting the timing gap during user access.
Affected Systems and Versions
Integrated Dell Remote Access Controller (iDRAC) by Dell versions below 4.40.00.00 are impacted by this vulnerability, leaving systems open to unauthorized privilege escalation.
Exploitation Mechanism
Attackers with authenticated access can take advantage of the race condition to gain elevated privileges during concurrent user sessions on the iDRAC web interface.
Mitigation and Prevention
Discover steps to secure your systems and prevent exploitation of CVE-2021-21539.
Immediate Steps to Take
Upgrade affected iDRAC9 installations to version 4.40.00.00 or above to mitigate this vulnerability. Monitor privileged user sessions closely to detect any unauthorized activity.
Long-Term Security Practices
Implement strict user access controls and regular security audits to identify and address potential vulnerabilities proactively.
Patching and Updates
Stay informed about security patches and updates from Dell to address known vulnerabilities, including TOCTOU race conditions.