Threats / vBulletin / CVE-2019-16759
CVE-2019-16759
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
vBulletin vulnerability
vBulletin PHP module contains a code injection vulnerability in the widget configuration parameter, allowing unauthenticated remote code execution through a crafted AJAX request.
Verdict
Today item — known-exploited.
An attacker can execute arbitrary PHP code on affected vBulletin installations by sending a malicious request to the widget rendering endpoint. This vulnerability has been actively exploited in the wild and poses critical risk to forum operators.
CISA KEV Yes · 2021-11-034EPSS 0.99728 (verify live)5Exploit Weaponized · public PoC6CVSS 9.8 (CISA)3CISA SSVC Exploitation: active · Automatable: yes · Impact: total3
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
6 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
Probability (EPSS)
EPSS 0.99728 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) · Affected: vBulletin, vBulletin. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-94 Code Injection — weakness family: Injection.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 771 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a functional/weaponized public exploit). Catalog entries: Metasploit module, nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft an AJAX request targeting the widget_php render route with malicious PHP code injected into the widgetConfig[code] parameter.
Business
The forum application processes and executes the injected code with server privileges, compromising system integrity.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I gain code execution context to read sensitive files, database credentials, or user data stored on the server.
Business
User accounts, private messages, and forum data become accessible to the attacker, resulting in data breach and privacy violations.
3
Lateral reach — past segmentation narrative 3
Attacker
I establish persistence by creating backdoor accounts, modifying application files, or installing web shells for continued access.
Business
The forum remains compromised even after patching, requiring forensic investigation and potential data recovery efforts.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05