CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:M/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
5.1%
Local Privilege Escalation in all Windows software frozen by PyInstaller in “onefile” mode.
The vulnerability is present only on Windows and in this particular case: If a software frozen by PyInstaller in “onefile” mode is launched by a (privileged) user who hashis/her “TempPath” resolving to a world writable directory. This is the case e.g. if the software is launched as a service or as a scheduled task using a system account (in which case TempPath will default to C:\Windows\Temp).
In order to be exploitable the software has to be (re)started after the attacker has launched the exploit program. So for a service launched at startup, a service restart is needed (e.g. after a crash or an upgrade).
While PyInstaller itself was not vulnerable, all Windows software frozen by PyInstaller in “onefile” mode is vulnerable.
CVSSv3 score 7.0 (High)
CVSSv3 vector CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected
No affected
The problem is patched in commits 42a67148b3bdf9211fda8499fdc5b63acdd7e6cc (fixed code) and be948cf0954707671aa499da17b10c86b6fa5e5c (recompiled bootloaders). Users should upgrade to PyInstaller version 3.6 and rebuild their software.
There is no known workaround. Users using PyInstaller to freeze their Windows software using “onefile” mode should upgrade PyInstaller and rebuild their software.
This vulnerability was discovered and reported by Farid AYOUJIL (@faridtsl), David HA, Florent LE NIGER and Yann GASCUEL (@lnv42) from Alter Solutions (@AlterSolutions) and fixed in collaboration with
Hartmut Goebel (@htgoebel, maintainer of PyInstaller).
PyInstaller is in urgent need of funding to make future security fixes happen, see <https://github.com/pyinstaller/pyinstaller/issues/4404> for details.
Vendor | Product | Version | CPE |
---|---|---|---|
pyinstaller | pyinstaller | * | cpe:2.3:a:pyinstaller:pyinstaller:*:*:*:*:*:*:*:* |
github.com/advisories/GHSA-7fcj-pq9j-wh2r
github.com/pyinstaller/pyinstaller/commit/42a67148b3bdf9211fda8499fdc5b63acdd7e6cc
github.com/pyinstaller/pyinstaller/commit/be948cf0954707671aa499da17b10c86b6fa5e5c
github.com/pyinstaller/pyinstaller/security/advisories/GHSA-7fcj-pq9j-wh2r
nvd.nist.gov/vuln/detail/CVE-2019-16784
CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:M/Au:N/C:P/I:P/A:P
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
5.1%