CVE-2019-6340
HIGHCVE-2019-6340 is a high-severity (CVSS 8.1) Deserialization of Untrusted Data vulnerability in drupal/core. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-25) — treat it as actively exploited and patch now. O3 Security confirms whether CVE-2019-6340 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Drupal Core Remote Code Execution Vulnerability
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-03-25. Federal agencies were required to remediate by 2022-04-15.
- 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-2019-6340.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2019-6340 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 368,770 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
drupal/core🐘drupal/core🐘drupal/core🐘drupal/drupal🐘drupal/drupal🐘drupal/drupalReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Some field types do not properly sanitize data from non-form sources in Drupal 8.5.x before 8.5.11 and Drupal 8.6.x before 8.6.10. This can lead to arbitrary PHP code execution in some cases. A site is only affected by this if one of the following conditions is met: The site has the Drupal 8 core RESTful Web Services (rest) module enabled and allows PATCH or POST requests, or the site has another web services module enabled, like JSON:API in Drupal 8, or Services or RESTful Web Services in Drupal 7. (Note: The Drupal 7 Services module itself does not require an update at this time, but you should apply other contributed updates associated with this advisory if Services is in use.)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | drupal/core | ≥ 8.6.0&&< 8.6.10 | 8.6.10 |
| 🐘Packagist | drupal/core | ≥ 7.0.0&&< 7.62.0 | 7.62.0 |
| 🐘Packagist | drupal/core | ≥ 8.0.0&&< 8.5.11 | 8.5.11 |
| 🐘Packagist | drupal/drupal | ≥ 7.0.0&&< 7.62.0 | 7.62.0 |
| 🐘Packagist | drupal/drupal | ≥ 8.0.0&&< 8.5.11 | 8.5.11 |
| 🐘Packagist | drupal/drupal | ≥ 8.6.0&&< 8.6.10 | 8.6.10 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Drupal < 8.6.10 / < 8.5.11 - REST Module Remote Code Execution
by Charles Fol · Feb 23, 2019
Drupal < 8.5.11 / < 8.6.10 - RESTful Web Services unserialize() Remote Command Execution (Metasploit)
by Metasploit · Mar 7, 2019
Drupal < 8.6.9 - REST Module Remote Code Execution
by leonjza · Feb 25, 2019
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for drupal/core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update drupal/core to 8.6.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-6340 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2019-6340 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2019-6340. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2019-6340 in your dependencies?
O3 detects CVE-2019-6340 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.