#VU49179 NULL pointer dereference in OpenSMTPD - CVE-2020-35680
Published: December 24, 2020 / Updated: December 29, 2020
Vulnerability identifier: #VU49179
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2020-35680
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
OpenSMTPD
OpenSMTPD
Software vendor:
OpenBSD
OpenBSD
Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in smtpd/lka_filter.c in certain configurations. A remote attacker can trigger denial of service conditions via a crafted pattern of client activity, because the filter state machine does not properly maintain the I/O channel between the SMTP engine and the filters layer.
Remediation
Install update from vendor's website.