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Identity Services EngineApplication · Cisco

CVE-2022-20959

MEDIUM · 5.4 CVSS v3.1 Published 2022-10-26
Fix available
A fix is available. Upgrade to 2.7.0 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

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
A vulnerability in the External RESTful Services (ERS) API of Cisco Identity Services Engine (ISE) Software could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface of an affected device. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by persuading an authenticated administrator of the web-based management interface to click a malicious link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.

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 · moderate confidence

This is a stored cross-site scripting (XSS) vulnerability in the External RESTful Services (ERS) API of Cisco Identity Services Engine (ISE) Software. The vulnerability stems from insufficient input validation, allowing an authenticated attacker to inject malicious script code through the ERS API that executes in the browser of an authenticated administrator viewing the affected interface.

MitigationApply the Cisco patch for CVE-2022-20959 when available. In the interim, restrict access to the ERS API to trusted users and monitor for suspicious administrative sessions.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
Identity Services EngineApplication
Affected:>= 2.4, < 2.7.0= 2.7.0= 3.0.0= 3.1= 3.2

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine Cisco ISE version
    Log into the ISE admin GUI and navigate to Administration > System > Licensing, or run 'show version' command via CLI. Record the exact version number (e.g., 2.6.0, 3.0.0, 3.1.0).
    Affected if Version falls within: >= 2.4 and < 2.7.0, OR equals 2.7.0, OR equals 3.0.0, OR equals 3.1, OR equals 3.2
  2. Verify ERS API is enabled
    In ISE GUI, go to Administration > System > Settings > API Settings. Check if 'Enable External RESTful Services' is turned ON.
    Affected if ERS API is enabled; if disabled, the vulnerability cannot be exploited
  3. Check ERS API access policy
    Navigate to Administration > System > User Management > ERS Settings. Review which user groups or admin users have 'ERS Admin' or 'ERS Operator' privileges.
    Affected if Untrusted or low-privilege users have ERS API access, allowing them to inject malicious scripts
  4. Audit ERS API logs for suspicious activity
    Go to Operations > RADIUS > Live Logs, or use 'show logging application ere.log' via CLI. Filter for ERS API requests. Look for unusual payloads in POST/PUT requests to ERS endpoints (e.g., /ers/config/...).
    Affected if Logs show unexpected or malformed API calls containing script tags or unusual encoding

You are affected if your Cisco ISE version is within the vulnerable range AND the ERS API is enabled and accessible to the attacker.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 2.7.0 or later
Fixed in 2.7.0
Interim mitigation

Apply the Cisco patch for CVE-2022-20959 when available. In the interim, restrict access to the ERS API to trusted users and monitor for suspicious administrative sessions.

Recommended fix Moderate confidence

Cisco ISE version 3.2 or later

  1. 1. Back up the current Cisco ISE configuration and verify backup integrity.
  2. 2. Review Cisco ISE release notes for version 3.2 or later to confirm the security fix for CVE-2022-20959 is included.
  3. 3. Plan maintenance window as upgrade requires downtime.
  4. 4. Download Cisco ISE version 3.2 (or latest stable release) from Cisco.com software downloads.
  5. 5. Follow Cisco ISE upgrade procedure: navigate to Administration > System > Maintenance > Software Upgrade in the ISE admin GUI.
  6. 6. Upload the upgrade bundle and initiate the upgrade.
  7. 7. After upgrade completes, verify the ISE services are running and accessible.
  8. 8. Validate that the ERS API functionality works correctly post-upgrade.
Caveat Upgrade may require downtime; verify compatibility with existing integrations and review upgrade path from your current version (some versions may require intermediate upgrades)

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

Fix this in Identity Services Engine Scoped from the published advisory
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,150
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Scan for this in your stack

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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-2022-20959 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