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Big Ip Access Policy ManagerApplication · F5

CVE-2021-22978

HIGH · 8.3 CVSS v3.1 Published 2021-02-12
Fix available
A fix is available. Upgrade to 13.1.3.5 / 14.1.3.1 or later.
See remediation →
90/100
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 version 16.0.x before 16.0.1, 15.1.x before 15.1.1, 14.1.x before 14.1.3.1, 13.1.x before 13.1.3.5, and all 12.1.x and 11.6.x versions, undisclosed endpoints in iControl REST allow for a reflected XSS attack, which could lead to a complete compromise of BIG-IP if the victim user is granted the admin role. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

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 cross-site scripting (XSS) vulnerability in undisclosed iControl REST API endpoints on F5 BIG-IP. The vulnerability allows attackers to inject malicious scripts through crafted requests that are reflected back to the victim user's browser, enabling session hijacking or arbitrary actions when an administrator unknowingly executes the payload.

MitigationApply F5 security updates for affected versions (16.0.1+, 15.1.1+, 14.1.3.1+, 13.1.3.5+). Until patched, restrict iControl REST access to trusted networks only and monitor for anomalous requests.

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:>= 11.6.1, <= 11.6.5>= 12.1.0, <= 12.1.5>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.3.1>= 15.1.0, < 15.1.1>= 16.0.0, < 16.0.1
Big Ip Advanced Firewall ManagerApplication
Affected:>= 11.6.1, <= 11.6.5>= 12.1.0, <= 12.1.5>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.3.1>= 15.1.0, < 15.1.1>= 16.0.0, < 16.0.1
Big Ip Advanced Web Application FirewallApplication
Affected:>= 11.6.1, <= 11.6.5>= 12.1.0, <= 12.1.5>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.3.1>= 15.1.0, < 15.1.1>= 16.0.0, < 16.0.1
Big Ip AnalyticsApplication
Affected:>= 11.6.1, <= 11.6.5>= 12.1.0, <= 12.1.5>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.3.1>= 15.1.0, < 15.1.1>= 16.0.0, < 16.0.1
Big Ip Application Acceleration ManagerApplication
Affected:>= 11.6.1, <= 11.6.5>= 12.1.0, <= 12.1.5>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.3.1>= 15.1.0, < 15.1.1>= 16.0.0, < 16.0.1
Big Ip Application Security ManagerApplication
Affected:>= 11.6.1, <= 11.6.5>= 12.1.0, <= 12.1.5>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.3.1>= 15.1.0, < 15.1.1>= 16.0.0, < 16.0.1
Big Ip Ddos Hybrid DefenderApplication
Affected:>= 11.6.1, <= 11.6.5>= 12.1.0, <= 12.1.5>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.3.1>= 15.1.0, < 15.1.1>= 16.0.0, < 16.0.1
Big Ip Domain Name SystemApplication
Affected:>= 11.6.1, <= 11.6.5>= 12.1.0, <= 12.1.5>= 13.1.0, < 13.1.3.5>= 14.1.0, < 14.1.3.1>= 15.1.0, < 15.1.1>= 16.0.0, < 16.0.1

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

CVSS:3.1/AV:N/AC:H/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 installed BIG-IP version
    Run `tmsh show /sys version` on the BIG-IP command line, or query the iControl REST endpoint GET /mgmt/tm/sys/version/ to retrieve the software version.
    Affected if The installed version falls within these ranges: 11.6.1 to 11.6.5, 12.1.0 to 12.1.5, 13.1.0 to 13.1.3.4, 14.1.0 to 14.1.3.0, 15.1.0 to 15.1.0, or 16.0.0 to 16.0.0.
  2. Verify iControl REST is accessible
    Confirm that the iControl REST API is exposed by attempting to access the endpoint GET /mgmt/tm/sys/ from a management interface or checking if port 443 (or custom mgmt port) accepts REST API requests.
    Affected if iControl REST API is reachable from network segments that include untrusted users, particularly the management network.
  3. Check which BIG-IP modules are provisioned
    Run `tmsh list sys provision` or query GET /mgmt/tm/sys/provision/ to list provisioned modules.
    Affected if Any of the following modules are provisioned: APM, AFM, ASM, Analytics, AAM, DNS, or DDoS Hybrid Defender.
  4. Review access logs for suspicious iControl REST requests
    Examine /var/log/audit for iControl REST API calls that may contain XSS payloads (look for unusual script tags or encoded characters in API request paths or parameters).

You are affected if your BIG-IP version is within the affected ranges AND iControl REST API is accessible from an untrusted network AND one or more affected modules (APM, AFM, ASM, Analytics, AAM, DNS, DDoS) are provisioned.

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.

From vendor data
Upgrade available Upgrade to 13.1.3.5 / 14.1.3.1 / 15.1.1 or later
Fixed in 13.1.3.514.1.3.115.1.1
Interim mitigation

Apply F5 security updates for affected versions (16.0.1+, 15.1.1+, 14.1.3.1+, 13.1.3.5+). Until patched, restrict iControl REST access to trusted networks only and monitor for anomalous requests.

Fix this in Big Ip Access Policy Manager Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,280
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.

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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-2021-22978 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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