Portal For ArcgisApplication · Esri

CVE-2021-29110

MEDIUM · 5.4 CVSS v3.1 Published 2021-10-01
Fix available
A fix is available. Upgrade to after 10.9 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Stored cross-site scripting (XSS) issue in Esri Portal for ArcGIS may allow a remote unauthenticated attacker to pass and store malicious strings in the home application.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-79

Untrusted input is placed into a web page without being neutralised, so an attacker's markup or script executes in another user's browser. That can hijack sessions, capture keystrokes, or silently perform actions as the victim. Fixing it properly means context-aware output encoding everywhere data meets HTML, backed by a content-security policy as a second line of defence.

General guidance for the cross-site scripting (xss) class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Portal For ArcgisApplication
Affected:<= 10.9

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 10.9
Vendor patch www.esri.com →
Recommended fix Moderate confidence

Apply Portal for ArcGIS Security 2021 Update 1 Patch (or upgrade to version containing the fix if a newer release is available)

  1. 1. Navigate to the Esri Support website or the official Esri ArcGIS Blog page for Portal for ArcGIS Security 2021 Update 1 Patch
  2. 2. Locate and download the Security 2021 Update 1 Patch for Portal for ArcGIS appropriate for your current version (10.9 or earlier)
  3. 3. Review the patch release notes to understand any prerequisites or installation requirements
  4. 4. Back up your Portal for ArcGIS configuration and data before applying the patch
  5. 5. Apply the Security 2021 Update 1 Patch following Esri's standard patching procedures
  6. 6. Verify the patch was applied successfully by checking the version and reviewing the patch documentation
  7. 7. Test the home application functionality to ensure the XSS vulnerability is remediated and normal operations are unaffected
Caveat Review patch release notes for any configuration changes or known issues specific to your deployment

Generated from the published advisory — verify against the referenced sources before acting.

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $900. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-29110 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-29110 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data