dbcve.org
Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 3 May 2022.
VbulletinApplication

CVE-2020-17496

CRITICAL · 9.8 CVSS v3.1 Published 2020-08-12
Fix available
A fix is available. Upgrade to after 5.6.2 or later.
See remediation →
100/100
Remediation priority · Urgent
In the wild High EPSS Public exploit Remotely reachable No privileges Zero-click Patch available

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
vBulletin 5.5.4 through 5.6.2 allows remote command execution via crafted subWidgets data in an ajax/render/widget_tabbedcontainer_tab_panel request. NOTE: this issue exists because of an incomplete fix for CVE-2019-16759.

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

vBulletin 5.5.4 through 5.6.2 contains a remote command execution vulnerability in the ajax/render/widget_tabbedcontainer_tab_panel endpoint. Attackers can inject malicious PHP code through crafted subWidgets data, allowing arbitrary command execution on the server. This vulnerability is an incomplete fix for CVE-2019-16759, indicating the original patch did not fully address the attack vector.

MitigationImmediately upgrade vBulletin to the latest patched version. If immediate patching is not possible, restrict access to the ajax/render/ endpoints via web server configuration or disable the widget system until the patch can be applied.

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
VbulletinApplication
Affected:>= 5.5.4, <= 5.6.2

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
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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. Check the installed vBulletin version
    Locate the version number in the admin control panel under Admin CP > Dashboard > Version, or inspect the includes/version.php file for the $config['vbversion'] value
    Affected if Installed version is between 5.5.4 and 5.6.2 inclusive
  2. Confirm the widget rendering endpoint exists
    Check if the path /ajax/render/widget_tabbedcontainer_tab_panel is accessible on the web server by reviewing web server configuration or attempting a request to the endpoint
    Affected if The endpoint responds to requests (vulnerable configuration)
  3. Search logs for exploitation attempts
    Review web server access logs for POST requests to /ajax/render/widget_tabbedcontainer_tab_panel containing suspicious patterns such as subWidgets data with phpinfo, system, exec, shell_exec, or base64 encoded commands
    Affected if Log entries contain exploit signatures matching the CVE-2020-17496 attack pattern

The environment is affected if vBulletin version is 5.5.4 through 5.6.2 AND the widget_tabbedcontainer_tab_panel endpoint is accessible without proper authentication controls.

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 a release after 5.6.2
Vendor patch forum.vbulletin.com →
Interim mitigation

Immediately upgrade vBulletin to the latest patched version. If immediate patching is not possible, restrict access to the ajax/render/ endpoints via web server configuration or disable the widget system until the patch can be applied.

Recommended fix High confidence

vBulletin 5.6.3 or later

  1. 1. Backup the vBulletin database and files before making any changes.
  2. 2. Download vBulletin 5.6.3 or later from the official vBulletin members area at https://members.vbulletin.com/
  3. 3. Extract the upgrade package and upload the files to the server, overwriting existing files.
  4. 4. Run the upgrade script by visiting /install/upgrade.php on the server.
  5. 5. After upgrade completes, verify the subWidgets parameter handling in widget_tabbedcontainer_tab_panel is patched.
  6. 6. Test that RCE is no longer possible via the ajax/render/widget_tabbedcontainer_tab_panel endpoint.
  7. 7. Ensure the server is monitored for any signs of compromise from this vulnerability.
Caveat Minor - upgrade should be straightforward but always test in staging first

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

Fix this in Vbulletin Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing8.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,080
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,928.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-17496 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2020-17496 in production — separate from our analysis above.

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.

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