Identity Services EngineApplication · Cisco
CVE-2020-3156
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 · uneditedA vulnerability in the logging component of Cisco Identity Services Engine could allow an unauthenticated remote attacker to conduct cross-site scripting attacks. The vulnerability is due to the improper validation of endpoint data stored in logs used by the web-based interface. An attacker could exploit this vulnerability by sending malicious endpoint data to the targeted system. An exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or to 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 · high confidenceCisco Identity Services Engine contains a stored XSS vulnerability in its logging component. The web interface does not properly validate endpoint data before storing it in logs, allowing attackers to embed malicious scripts. When administrators view the affected logs through the ISE web UI, the embedded scripts execute in their browser context.
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
= 2.6.0= 2.7CVSS 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
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
-
Confirm Cisco ISE installationAccess the ISE admin CLI or web UI and identify if Cisco Identity Services Engine is deployed. In the web UI, check the dashboard or run 'show version' in the CLI.Affected if Cisco ISE is confirmed to be installed
-
Determine installed ISE versionIn the ISE web UI, navigate to Administration > System > Licensing or run 'show version' in the CLI to retrieve the exact software version number.Affected if The version is 2.6.0 or 2.7 (exact matches to affected versions)
-
Verify logging is enabledIn the ISE web UI, go to Administration > Logging > Logging Categories to confirm that logging is enabled for endpoint-related events.Affected if Logging is enabled and the system processes endpoint data into logs
-
Check web UI accessConfirm the ISE web administration interface is accessible. Verify whether it is exposed to untrusted networks or limited to specific admin IP ranges.Affected if The ISE web interface is accessible to administrators who would view logs
A user is affected if they have Cisco ISE versions 2.6.0 or 2.7 deployed with the web interface and logging enabled, and administrators view endpoint data in the ISE web UI logs.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataApply the Cisco ISE vendor patch when available. In the interim, limit administrative access to the ISE web interface to trusted IP addresses only and monitor logs for suspicious endpoint data patterns.
Fix this in Identity Services Engine
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,880.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3156 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-3156 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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