Improper Check for Dropped Privileges in zsh - CVE-2019-20044
Published: March 19, 2020
Vulnerability identifier: #VU26210
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear
CVE-ID: CVE-2019-20044
CWE-ID: CWE-273
Exploitation vector: Local access
Exploit availability:
Public exploit is available
Vendor: SourceForge
Affected software:
zsh
zsh
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to Zsh fails to overwrite the saved uid, so the original privileges, dropped by the --no-PRIVILEGED option, can be restored by
executing MODULE_PATH=/dir/with/module zmodload with a module that calls
setuid(). A local user can execute arbitrary commands on the system with elevated privileges.
How to mitigate CVE-2019-20044
Install updates from vendor's website.