CVE-2020-35680

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.

• CWE-476

• https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1Patch, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/
• https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/Third Party Advisory
• https://security.gentoo.org/glsa/202105-12Third Party Advisory
• https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html
• https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1Patch, Third Party Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/
• https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/Third Party Advisory
• https://security.gentoo.org/glsa/202105-12Third Party Advisory
• https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html

Published

Dec 24, 2020

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2020-35675BigProf Online Invoicing System before 3.0 offers a function…8.8
• CVE-2020-35676BigProf Online Invoicing System before 3.1 fails to correctl…6.1
• CVE-2020-35677BigProf Online Invoicing System before 4.0 fails to adequate…4.8
• CVE-2020-35678Autobahn|Python before 20.12.3 allows redirect header inject…6.1
• CVE-2020-35679smtpd/table.c in OpenSMTPD before 6.8.0p1 lacks a certain re…7.5
• CVE-2020-3568A vulnerability in the antispam protection mechanisms of Cis…5.8
• CVE-2020-35681Django Channels 3.x before 3.0.3 allows remote attackers to …7.4
• CVE-2020-35682Zoho ManageEngine ServiceDesk Plus before 11134 allows an Au…8.8
• CVE-2020-35683An issue was discovered in HCC Nichestack 3.0. The code that…7.5
• CVE-2020-35684An issue was discovered in HCC Nichestack 3.0. The code that…7.5
• CVE-2020-35685An issue was discovered in HCC Nichestack 3.0. The code that…9.1
• CVE-2020-35686The SECOMN service in Sound Research DCHU model software com…7.8