Authorization weaknesses
The application fails to check whether this user may access a resource or perform an action.
CWE-863 · CISA KEV
Reading and practice labs · Free account for labs. Basic HTTP knowledge; some labs use Burp Suite.
Exploited. On CISA's list since 2021-11-03, and used by ransomware.
F5 BIG-IP and BIG-IQ Centralized Management iControl REST Remote Code Execution Vulnerability
CVE-2021-22986 · F5 BIG-IP and BIG-IQ Centralized Management · Published 2021-03-31
How bad would it be?
9.8 out of 10
CVSS rates it critical: about as damaging as flaws get.
How likely is it to be used?
over 99%
Estimated chance of exploitation in the next 30 days, among the top 1% of all scored flaws (EPSS, 2026-10-29).
Is it already being used?
Yes
CISA has seen it exploited in real attacks. For US government agencies the fix is deadline passed 1808 days ago (2021-11-17).
What CISA says to do
Apply updates per vendor instructions.
F5 BIG-IP and BIG-IQ Centralized Management contain a remote code execution vulnerability in the iControl REST interface that allows unauthenticated attackers with network access to execute system commands, create or delete files, and disable services.
What the flaw is
On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, and 12.1.x before 12.1.5.3 amd BIG-IQ 7.1.0.x before 7.1.0.3 and 7.0.0.x before 7.0.0.2, the iControl REST interface has an unauthenticated remote command execution vulnerability. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.
From the NVD.
Fixes and advisories
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Explore this week’s weaknesses and all learning topics
Understand the kind of weakness behind this flaw. These resources teach the weakness, rather than reproduce this specific CVE. Follow the vendor's advice above to fix the affected product.
Server-side request forgery
Input makes a server send a request to an unintended destination.
CWE-918 · NVD record: 134c704f-9b21-4f2e-91b3-4a467353bcc0; NVD record: nvd@nist.gov
Reading and practice labs · Free account for labs. Basic HTTP knowledge; some labs use Burp Suite.
CWE is a catalogue of weakness types. Labels come from the sources shown and can differ or change. Resource matches reviewed 16 October 2026.
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Exploited flaws from CISA's KEV catalogue. Chance of exploitation from EPSS by FIRST. Descriptions and scores from the NVD. This product uses the NVD API but is not endorsed or certified by the NVD.