CVE-2019-16759 — Vbulletin
CRITICALCVE-2019-16759 is a critical-severity (CVSS 9.8) Code Injection vulnerability in vbulletin vbulletin. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
vBulletin 5.x through 5.5.4 allows remote command execution via the widgetConfig[code] parameter in an ajax/render/widget_php routestring request.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03. Federal agencies were required to remediate by 2022-05-03.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2019-16759.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2019-16759 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
Description
vBulletin 5.x through 5.5.4 allows remote command execution via the widgetConfig[code] parameter in an ajax/render/widget_php routestring request.
Affected Products
vbulletinvbulletinResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
vBulletin 5.x - Remote Command Execution (Metasploit)
by r00tpgp · Sep 30, 2019
vBulletin 5.0 < 5.5.4 - 'widget_php ' Unauthenticated Remote Code Execution
by anonymous · Sep 23, 2019
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every vbulletin vbulletin deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2019-16759 yet — track the vbulletin vbulletin advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
How to detect CVE-2019-16759
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2019-16759 -u https://target- Template
- vBulletin 5.0.0-5.5.4 - Remote Command Execution
- Severity
- critical
- Impact
- Successful exploitation of this vulnerability could allow an attacker to execute arbitrary commands on the target system.
- Remediation
- Upgrade vBulletin to a version that is not affected by CVE-2019-16759.
Template by ProjectDiscovery nuclei-templates (madrobot), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2019-16759 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.