Permissions, Privileges, and Access Controls in OpenSMTPD - CVE-2020-8793
Published: February 25, 2020 / Updated: September 23, 2021
Vulnerability identifier: #VU25586
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:H/SI:H/SA:H/E:P/U:Clear
CVE-ID: CVE-2020-8793
CWE-ID: CWE-264
Exploitation vector: Local access
Exploit availability:
Public exploit is available
Vendor: OpenBSD
Affected software:
OpenSMTPD
OpenSMTPD
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to the application does not drop privileges when executing the "/usr/sbin/smtpctl" application with a "-bi" command-line argument. A local user can leverage this behavior and use a specially crafted hardlink to execute arbitrary code on the system with elevated privileges.
How to mitigate CVE-2020-8793
Install updates from vendor's website.