CVE-2020-35680

HIGH

OpenSMTPD < 6.8.0p1 - Denial of Service via NULL Pointer Dereference in lka_filter.c

Title source: llm

Description

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.

References (6)

Core 6

Core References

Third Party Advisory x_refsource_misc

https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/

Mailing List x_refsource_misc

https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html

Patch, Third Party Advisory x_refsource_misc

https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1

View Patch ZIP pw:eip

Mailing List, Third Party Advisory vendor-advisory x_refsource_fedora

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/

Mailing List, Third Party Advisory vendor-advisory x_refsource_fedora

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/

Third Party Advisory vendor-advisory x_refsource_gentoo

https://security.gentoo.org/glsa/202105-12

Scores

CVSS v3 7.5

EPSS 0.0358

EPSS Percentile 87.9%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Details

CWE

CWE-476

Status published

Products (4)

fedoraproject/fedora 32

fedoraproject/fedora 33

opensmtpd/opensmtpd 6.8.0 (2 CPE variants)

opensmtpd/opensmtpd < 6.8.0

Published Dec 24, 2020

Tracked Since Feb 18, 2026