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Big Ip Access Policy ManagerApplication · F5

CVE-2020-5948

CRITICAL · 9.6 CVSS v3.1 Published 2020-12-11
Fix available
A fix is available. Upgrade to 13.1.3.5 / 14.1.2.8 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges

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
On BIG-IP versions 16.0.0-16.0.0.1, 15.1.0-15.1.0.5, 14.1.0-14.1.2.7, 13.1.0-13.1.3.4, 12.1.0-12.1.5.2, and 11.6.1-11.6.5.2, undisclosed endpoints in iControl REST allow for a reflected XSS attack, which could lead to a complete compromise of the BIG-IP system if the victim user is granted the admin role.

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 confidence

Reflected XSS vulnerability in undisclosed iControl REST API endpoints on F5 BIG-IP. Attackers can craft malicious URLs that, when clicked by an authenticated admin user, execute arbitrary JavaScript in the admin's session context, enabling complete system compromise.

MitigationApply F5 security patches for the affected versions (upgrade to patched releases). Restrict iControl REST access to trusted management networks and consider disabling unused iControl REST endpoints.

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
Big Ip Access Policy ManagerApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1= 16.0.0
Big Ip Advanced Firewall ManagerApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1= 16.0.0
Big Ip AnalyticsApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1= 16.0.0
Big Ip Application Acceleration ManagerApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1= 16.0.0
Big Ip Application Security ManagerApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1= 16.0.0
Big Ip Domain Name SystemApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1= 16.0.0
Big Ip Fraud Protection ServiceApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1= 16.0.0
Big Ip Global Traffic ManagerApplication
Affected:>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.2.8>= 15.0.0, < 15.1.1= 16.0.0

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
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

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. Identify the installed BIG-IP version
    Run `tmsh show /sys version` from the command line or check System > About in the web UI to retrieve the exact software version
    Affected if The version falls within 13.1.0 to 13.1.3.4, 14.1.0 to 14.1.2.7, 15.0.0 to 15.1.0, or equals 16.0.0
  2. Determine which BIG-IP modules are provisioned
    Run `tmsh list /sys provision` to list all provisioned modules (such as APM, AFM, ASM, GTM, etc.)
    Affected if Any of the affected modules (APM, AFM, Analytics, AAM, ASM, DNS, FPS, GTM) are provisioned on the system
  3. Verify iControl REST access is enabled
    Check if the iControl REST service is listening by reviewing the management IP accessibility on ports 443 or 8443, or inspect the BIG-IP configuration for iControl REST settings
    Affected if iControl REST API endpoints are accessible over the network (not disabled or restricted to localhost)
  4. Confirm authentication to iControl REST is possible
    Attempt to access the iControl REST API endpoint with valid admin credentials using a tool like curl (e.g., `curl -k -u admin:password https://<mgmt-ip>/mgmt/tm/`)
    Affected if The API responds with valid JSON and does not require additional authentication beyond the admin session

You are affected if your BIG-IP version matches the vulnerable ranges AND any of the listed modules are provisioned AND iControl REST is accessible to an authenticated admin user.

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 13.1.3.5 / 14.1.2.8 / 15.1.1 or later
Fixed in 13.1.3.514.1.2.815.1.1
Interim mitigation

Apply F5 security patches for the affected versions (upgrade to patched releases). Restrict iControl REST access to trusted management networks and consider disabling unused iControl REST endpoints.

Recommended fix High confidence

Upgrade to BIG-IP 13.1.3.5+ / 14.1.2.8+ / 15.1.1+ / 16.0.0.2+ (or latest stable release)

  1. 1. Identify the exact BIG-IP product module and version currently installed (e.g., run 'tmsh show sys version' or check the web UI).
  2. 2. Determine the appropriate fixed version based on current version: for 13.1.x upgrade to 13.1.3.5 or later; for 14.1.x upgrade to 14.1.2.8 or later; for 15.0.x-15.1.0.x upgrade to 15.1.1 or later; for 16.0.0-16.0.0.1 upgrade to 16.0.0.2 or later.
  3. 3. Review the F5 release notes for the target version to understand changes and requirements.
  4. 4. Plan maintenance window as upgrades may require service interruption.
  5. 5. Backup current BIG-IP configuration using 'tmsh save sys config' or the web UI.
  6. 6. Download the target hotfix or maintenance release from F5 Networks support portal (support.f5.com).
  7. 7. Perform the upgrade following F5 upgrade documentation: upload the ISO/image, verify integrity, and install via web UI or tmsh.
  8. 8. After reboot, verify the system is operational and the new version is running.
Caveat Review F5 release notes for the target version for potential configuration or compatibility changes; some upgrades may require additional steps or have deprecated features.

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

Fix this in Big Ip Access Policy Manager Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2020-5948 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data