Security readout for executives and security teams
Plain-English summary
Dell iDRAC9 before 4.40.40.00 has a browser-side cross-site scripting flaw. An attacker would need to convince an administrator or user to open a crafted link, which could run malicious script in that person’s browser. This is not listed as known exploited in KEV.
Executive priority
Treat as a moderate-priority management-plane issue. It requires user interaction and has no cited active exploitation, but iDRAC is sensitive infrastructure. Patch during the next firmware maintenance window, sooner for internet-exposed or broadly reachable management networks.
Technical view
CVE-2021-21577 is a DOM-based XSS issue in Dell EMC iDRAC9 prior to 4.40.40.00, mapped to CWE-79. CVSS 3.1 is 6.1: network reachable, low complexity, no privileges required, user interaction required, changed scope, low confidentiality and integrity impact, no availability impact.
Likely exposure
Exposure is likely limited to organizations running Dell iDRAC9 firmware below 4.40.40.00, especially where administrators access iDRAC web interfaces. The source bundle does not identify affected hardware models beyond iDRAC9.
Exploitation context
The source states a remote attacker could exploit this by tricking a victim into following a specially crafted link. KEV status is false in the bundle, and no provided source supports active exploitation.
Researcher notes
Evidence is limited to the CVE record and Dell advisory reference in the bundle. The provided data confirms DOM XSS, version boundary, CVSS, and attack preconditions, but does not include exploit details, affected server model list, or Dell’s full remediation text.
Mitigation direction
- Inventory Dell iDRAC9 deployments and identify firmware versions.
- Upgrade affected iDRAC9 systems to 4.40.40.00 or later per Dell guidance.
- Review Dell advisory 000189193 for product-specific remediation details.
- Warn administrators not to open unexpected iDRAC links from untrusted sources.
Validation and detection
- Confirm each iDRAC9 asset is running 4.40.40.00 or newer.
- Check vulnerability scanner results against CVE-2021-21577 findings.
- Review admin email and proxy telemetry for suspicious iDRAC link lures.
- Document exceptions where firmware cannot yet be updated.
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-2021-21577 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.