CVE-2019-16784
HIGHCVE-2019-16784 is a high-severity (CVSS 7.8) CWE-250 vulnerability in pyinstaller. O3 Security confirms whether CVE-2019-16784 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Local Privilege Escalation in PyInstaller
Real-World Exposure
pyinstallerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
In PyInstaller before version 3.6, only on Windows, a local privilege escalation vulnerability is present in this particular case: If a software using PyInstaller in "onefile" mode is launched by a privileged user (at least more than the current one) which have his "TempPath" resolving to a world writable directory. This is the case for example if the software is launched as a service or as a scheduled task using a system account (TempPath will be C:\Windows\Temp). In order to be exploitable the software has to be (re)started after the attacker launch the exploit program, so for a service launched at startup, a service restart is needed (e.g. after a crash or an upgrade).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pyinstaller | all versions | 3.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyinstaller. 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 pyinstaller to 3.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-16784 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-2019-16784 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-2019-16784. 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-2019-16784 in your dependencies?
O3 detects CVE-2019-16784 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.