CVE-2019-16784: Local Privilege Escalation in PyInstaller

CVE-2019-16784 · Severity: low · CVSS 3.1 · Published 2020-01-14

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).

Technologies: pyinstaller (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2019-16784 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2019-16784 being exploited in the wild.
How severe is CVE-2019-16784?
Low severity, with a CVSS score of 3.1, published 14 January 2020.
Which products and versions are affected?
pyinstaller (PyPI) ECOSYSTEM:introduced=0,fixed=3.6.
Is there a fix for CVE-2019-16784?
Yes. pyinstaller (PyPI): upgrade to 3.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2019-16784?
Check whether you run pyinstaller (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • pyinstaller (PyPI): upgrade to 3.6 or later
    pip install "pyinstaller>=3.6"

Affected products

  • pyinstaller (PyPI) ECOSYSTEM:introduced=0,fixed=3.6

Identifiers

  • CVE-2019-16784
  • GHSA-7fcj-pq9j-wh2r
  • PYSEC-2020-175

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