Arch Linux Security Advisory ASA-202101-18
=========================================
Severity: High
Date    : 2021-01-12
CVE-ID  : CVE-2020-35679 CVE-2020-35680
Package : opensmtpd
Type    : multiple issues
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1381

Summary
======
The package opensmtpd before version 6.8.0p2-1 is vulnerable to
multiple issues including information disclosure and denial of service.

Resolution
=========
Upgrade to 6.8.0p2-1.

# pacman -Syu "opensmtpd>=6.8.0p2-1"

The problems have been fixed upstream in version 6.8.0p2.

Workaround
=========
None.

Description
==========
- CVE-2020-35679 (information disclosure)

smtpd/table.c in OpenSMTPD before 6.8.0p1 lacks a certain regfree,
which might allow attackers to trigger a "very significant" memory leak
via messages to an instance that performs many regex lookups.

- CVE-2020-35680 (denial of service)

smtpd/lka_filter.c in OpenSMTPD before 6.8.0p1, in certain
configurations, allows remote attackers to cause a denial of service
(NULL pointer dereference and daemon crash) 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.

Impact
=====
A malicious remote user might read memory or crash the service.

References
=========
https://github.com/openbsd/src/commit/79a034b4aed29e965f45a13409268290c9910043
https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1
https://security.archlinux.org/CVE-2020-35679
https://security.archlinux.org/CVE-2020-35680