Security readout for executives and security teams
Plain-English summary
Dell iDRAC9 firmware before 4.40.40.00 has a browser-side cross-site scripting flaw. An attacker could send a crafted link and, if an administrator opens it, run malicious HTML or JavaScript in that browser session. This is not described as direct server compromise, but iDRAC is sensitive management infrastructure.
Executive priority
Treat as a moderate-priority management-plane issue. Schedule firmware updates promptly, with higher urgency for internet-reachable iDRAC interfaces or administrators who manage critical servers through the web UI.
Technical view
CVE-2021-21576 is a DOM-based XSS issue in Dell EMC iDRAC9 prior to 4.40.40.00. The CVSS 3.1 score is 6.1 with network attack vector, low complexity, no privileges required, required user interaction, changed scope, and low confidentiality and integrity impact.
Likely exposure
Organizations using Dell servers with iDRAC9 firmware below 4.40.40.00 are potentially exposed, especially where administrators access the iDRAC web interface from normal browsing environments or where management interfaces are reachable beyond restricted admin networks.
Exploitation context
The provided sources describe remote exploitation by tricking a victim into following a crafted link. KEV is false, and the bundle does not provide evidence of active exploitation or a public exploit.
Researcher notes
This is CWE-79 DOM XSS with UI:R and PR:N. The issue affects browser execution context after social engineering, not availability. The source bundle does not include exploit details, proof of active exploitation, or additional affected Dell products beyond iDRAC9.
Mitigation direction
- Inventory Dell iDRAC9 firmware versions across managed servers.
- Upgrade affected iDRAC9 firmware to 4.40.40.00 or later per Dell guidance.
- Restrict iDRAC web access to trusted management networks.
- Warn administrators not to open untrusted iDRAC links.
- Review Dell advisory for any environment-specific remediation details.
Validation and detection
- Confirm each iDRAC9 device reports firmware 4.40.40.00 or later.
- Check whether iDRAC web interfaces are reachable from untrusted networks.
- Verify administrators use hardened workstations for iDRAC access.
- Review browser, proxy, and access logs for suspicious iDRAC link activity.
- Track remediation status for any device still below the fixed version.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-21576 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.dell.com/support/kbdoc/000189193CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.