CVE-2021-21578 in iDRAC9
Summary
by MITRE • 08/03/2021
Dell EMC iDRAC9 versions prior to 4.40.40.00 contain an open redirect vulnerability. A remote unauthenticated attacker may exploit this vulnerability to redirect users to arbitrary web URLs by tricking the victim users to click on maliciously crafted links.
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Analysis
by VulDB Data Team • 08/07/2021
The vulnerability identified as CVE-2021-21578 affects Dell EMC iDRAC9 remote management controllers running versions prior to 4.40.40.00, representing a critical open redirect flaw that enables unauthorized redirection of user sessions to malicious web addresses. This security weakness stems from insufficient validation of redirect parameters within the iDRAC9 web interface, allowing attackers to manipulate URL redirection logic without authentication requirements. The vulnerability manifests when the system processes redirect URLs that are not properly sanitized or validated, creating a pathway for malicious actors to craft deceptive links that appear legitimate to unsuspecting users. Such open redirect vulnerabilities are particularly dangerous in remote management contexts where administrative access to critical infrastructure is involved, as they can serve as initial entry points for more sophisticated attacks.
The technical implementation of this flaw resides in the web application layer of iDRAC9, where redirect functionality is improperly implemented without adequate input validation or sanitization measures. When users click on maliciously crafted links containing crafted redirect parameters, the system fails to verify the destination URL against a whitelist of approved domains or perform proper URL validation checks. This allows attackers to specify arbitrary URLs in redirect parameters, potentially leading to phishing attacks, credential harvesting, or further exploitation of the target environment. The vulnerability operates at the application level and does not require authentication credentials to exploit, making it particularly concerning for network administrators who may inadvertently click on compromised links while monitoring or managing remote systems. This weakness aligns with CWE-601 open redirect vulnerability classification and represents a significant risk to the integrity of user sessions and the overall security posture of managed infrastructure.
The operational impact of CVE-2021-21578 extends beyond simple redirection attacks, as it can serve as a stepping stone for more advanced exploitation techniques within enterprise environments. Attackers can leverage this vulnerability to redirect users to phishing pages designed to capture administrative credentials for the iDRAC9 interface, potentially gaining full remote access to critical infrastructure components. The implications are particularly severe in environments where iDRAC9 is used for remote system management, as administrators may be tricked into redirecting to malicious sites while performing routine maintenance or monitoring tasks. This vulnerability can also facilitate credential stuffing attacks or be combined with other exploitation techniques to escalate privileges within the managed environment. The risk assessment must consider the potential for lateral movement within networks where iDRAC9 devices are deployed, as successful exploitation could provide attackers with persistent access to remote management interfaces that control critical system functions.
Mitigation strategies for CVE-2021-21578 focus primarily on updating iDRAC9 firmware to version 4.40.40.00 or later, which contains the necessary patches to address the open redirect vulnerability. Organizations should implement immediate firmware updates across all affected iDRAC9 devices within their infrastructure, prioritizing critical systems and those with direct internet exposure. Network administrators should also consider implementing additional security controls such as web application firewalls or content filtering solutions that can detect and block suspicious redirect patterns. Monitoring for anomalous redirect behavior in network logs and implementing security awareness training for administrators can help identify potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation and output encoding practices as outlined in the OWASP Top Ten security guidelines, emphasizing the need for defensive programming techniques that prevent malicious input from being processed as legitimate commands. Organizations should also conduct thorough vulnerability assessments to identify any other instances of similar weaknesses within their remote management infrastructure, as this vulnerability represents a common pattern that may exist in other components of the system.