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Big Ip Access Policy ManagerApplication · F5

CVE-2021-23023

HIGH · 7.8 CVSS v3.1 Published 2021-06-10
Fix available
A fix is available. Upgrade to 7.2.1.3 or later.
See remediation →
81/100
Remediation priority · High
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 version 7.2.1.x before 7.2.1.3 and 7.1.x before 7.1.9.9 Update 1, a DLL hijacking issue exists in cachecleaner.dll included in the BIG-IP Edge Client Windows Installer. Note: Software versions which have reached End of Technical Support (EoTS) 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

A DLL hijacking vulnerability exists in cachecleaner.dll within the BIG-IP Edge Client Windows Installer. An attacker could place a malicious DLL in a location where the application loads it, potentially executing arbitrary code with the privileges of the affected user. This affects versions 7.2.1.x before 7.2.1.3 and 7.1.x before 7.1.9.9 Update 1.

MitigationUpgrade BIG-IP Edge Client Windows Installer to version 7.2.1.3 or later, or 7.1.9.9 Update 1 or later. Users should only run the client on trusted systems and avoid downloading or placing untrusted DLLs in the application's directory.

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:>= 7.1.6, <= 7.1.9.9>= 7.2.1, < 7.2.1.3

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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/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 BIG-IP Edge Client installation
    Open Windows Registry Editor and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall or check C:\Program Files\F5 Networks for a folder named 'BIG-IP Edge Client'
    Affected if The application is not installed on the system, the vulnerability does not apply
  2. Find installed version number
    In the registry uninstall key for BIG-IP Edge Client, locate the 'DisplayVersion' value, or right-click the installer executable in Program Files and select Properties > Details to view the File Version
    Affected if The version falls within 7.1.6 to 7.1.9.9 (inclusive) OR 7.2.1 to 7.2.1.2 (inclusive), indicating the installation is vulnerable
  3. Locate cachecleanler.dll
    Navigate to the BIG-IP Edge Client installation directory (typically C:\Program Files\F5 Networks\BIG-IP Edge Client\) and search for cachecleaner.dll
    Affected if The DLL file exists in the installation directory, confirming the vulnerable component is present
  4. Check directory write permissions
    Right-click the BIG-IP Edge Client installation folder, select Properties > Security, and verify which users have Write or Modify permissions. Alternatively, run 'icacls "C:\Program Files\F5 Networks\BIG-IP Edge Client"' from an elevated command prompt
    Affected if Non-admin users or untrusted accounts have Write permissions to the installation directory, allowing them to place a malicious DLL
  5. Identify running processes
    Open Task Manager, look for any BIG-IP Edge Client processes (such as epmm.exe, f5mcp.exe, or bigipnec.exe) running under user contexts
    Affected if The client is actively running, meaning the vulnerable DLL could be loaded if the application attempts to use the cachecleaner functionality

A user is affected if BIG-IP Edge Client Windows Installer version 7.1.6-7.1.9.9 or 7.2.1-7.2.1.2 is installed with cachecleaner.dll present in an unprotected installation directory.

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 7.2.1.3 or later
Fixed in 7.2.1.3
Interim mitigation

Upgrade BIG-IP Edge Client Windows Installer to version 7.2.1.3 or later, or 7.1.9.9 Update 1 or later. Users should only run the client on trusted systems and avoid downloading or placing untrusted DLLs in the application's directory.

Fix this in Big Ip Access Policy Manager Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

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-2021-23023 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