CVE-2021-21508 Overview
CVE-2021-21508 is a plain-text password storage vulnerability in Dell VxRail Manager affecting versions before 7.0.200. The flaw allows a user with sys-admin privileges to read credentials stored in clear text on the appliance. An attacker who recovers these credentials can authenticate to the vulnerable application with the privileges of the compromised account. The issue is classified under CWE-532: Insertion of Sensitive Information into Log File and requires local access with high privileges to exploit.
Critical Impact
Disclosure of plain-text user credentials in Dell VxRail Manager enables lateral movement and privilege reuse against the affected hyperconverged infrastructure.
Affected Products
- Dell VxRail Manager versions prior to 7.0.200
- Dell VxRail hyperconverged infrastructure appliances running affected firmware
- Environments managed by vulnerable VxRail Manager instances
Discovery Timeline
- 2026-05-22 - CVE-2021-21508 published to NVD
- 2026-05-22 - Last updated in NVD database
Technical Details for CVE-2021-21508
Vulnerability Analysis
The vulnerability resides in how Dell VxRail Manager handles credential storage. Affected versions write user credentials to disk or configuration artifacts without encryption or hashing. A sys-admin user with shell or management access can read these artifacts and recover usable plain-text credentials. The exposed credentials can then be replayed against the application to impersonate the compromised account.
The issue maps to [CWE-532], which covers improper protection of sensitive information through file-based storage. The attack vector is local, meaning the attacker must already hold an authenticated foothold on the appliance. With an EPSS score of 0.016% and a percentile of 3.74, in-the-wild exploitation interest is low, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.
Root Cause
The root cause is the storage of authentication material in plain text within VxRail Manager. Developers did not apply encryption, hashing, or restricted access controls to the files or fields holding these secrets. Any actor with sys-admin rights to the management plane inherits direct read access to the stored credentials.
Attack Vector
Exploitation requires local access and high privileges on the VxRail Manager appliance. A sys-admin user enumerates configuration or log files containing stored credentials, extracts the plain-text values, and reuses them to authenticate to the vulnerable application or downstream services that share credentials. No user interaction is required, and the scope remains unchanged.
No verified public proof-of-concept code is available. Refer to the Dell Security Knowledge Base for vendor technical details.
Detection Methods for CVE-2021-21508
Indicators of Compromise
- Unexpected access to VxRail Manager configuration files or log directories by sys-admin accounts
- Successful authentications to VxRail Manager from new hosts using existing service accounts shortly after sys-admin file access events
- Outbound transfer of configuration archives or log bundles from VxRail Manager appliances
Detection Strategies
- Audit file access events on VxRail Manager for reads of credential-bearing files by interactive sys-admin sessions
- Correlate sys-admin shell activity with subsequent authentication events that reuse the same credentials
- Hunt for credential strings in exported support bundles, snapshots, or backups that leave the appliance
Monitoring Recommendations
- Centralize VxRail Manager audit logs in a SIEM and alert on sys-admin command execution outside change windows
- Monitor for credential reuse across VxRail Manager, vCenter, and ESXi hosts using identity correlation
- Track configuration export, backup, and scp/sftp activity originating from the VxRail Manager appliance
How to Mitigate CVE-2021-21508
Immediate Actions Required
- Upgrade Dell VxRail Manager to version 7.0.200 or later as specified in the Dell advisory
- Rotate all credentials that may have been stored in plain text on affected appliances, including service and integration accounts
- Review sys-admin account membership and remove unnecessary privileged users from VxRail Manager
Patch Information
Dell addresses the vulnerability in VxRail 7.0.200 and later. Apply the upgrade using the standard VxRail lifecycle management workflow. Consult the Dell Security Knowledge Base for fixed build numbers and upgrade prerequisites.
Workarounds
- Restrict sys-admin access to VxRail Manager to a minimal set of named administrators until patching completes
- Place VxRail Manager on a dedicated management network reachable only through jump hosts with session recording
- Treat all credentials present on unpatched appliances as compromised and rotate them after upgrade
# Verify the running VxRail Manager version before and after patching
vxrail-version --show
# Expected output after remediation: version >= 7.0.200
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
