CVE-2021-21990Public exploitNetwork attack vector

Browser script execution via unsanitized redirect header

Published May 11, 2021 · Updated Aug 3, 2024

Reflected cross-site scripting in affected VMware Workspace ONE UEM Console releases allows remote attackers to execute script in an iOS user's browser. The IsMamEnrollmentEnabled enrollment endpoint copies an untrusted Referer header into a redirect Location header without validating its scheme. A victim must follow a crafted enrollment request in Safari on iOS; a data URI then executes JavaScript in that browser context, enabling access to session data or actions as the victim.

CVSS severity6.1
Medium
EPSS probability0.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected cross-site scripting in affected VMware Workspace ONE UEM Console releases allows remote attackers to execute script in an iOS user's browser. The IsMamEnrollmentEnabled enrollment endpoint copies an untrusted Referer header into a redirect Location header without validating its scheme. A victim must follow a crafted enrollment request in Safari on iOS; a data URI then executes JavaScript in that browser context, enabling access to session data or actions as the victim.

The record

CVE
CVE-2021-21990
Published
May 11, 2021
Updated
Aug 3, 2024
Vendor
VMware
Product
Workspace ONE UEM
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=VMware Workspace one UEM console (2102 prior to 21.2.0.8, 2101 prior to 21.1.0.14, 2011 prior to 20.11.0.27, 2010 prior to 20.10.0.16,2008 prior to 20.8.0.28, 2007 prior to 20.7.0.14,2006 prior to 20.6.0.19, 2005 prior to 20.5.0.46, 2004 prior to 20.4.0.21, 2003 prior to 20.3.0.23, 2001 prior to 20.1.0.32, 1912 prior to 19.12.0.24)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

VMware · Workspace ONE UEMversion=VMware Workspace one UEM console (2102 prior to 21.2.0.8, 2101 prior to 21.1.0.14, 2011 prior to 20.11.0.27, 2010 prior to 20.10.0.16,2008 prior to 20.8.0.28, 2007 prior to 20.7.0.14,2006 prior to 20.6.0.19, 2005 prior to 20.5.0.46, 2004 prior to 20.4.0.21, 2003 prior to 20.3.0.23, 2001 prior to 20.1.0.32, 1912 prior to 19.12.0.24)

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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