CVE-2020-35680
mediumpriority · track · 31EPSS 0.037 · 90 %ileEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (5)
Products and version ranges known to be affected.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (22)
External citations — patches, advisories, analysis.
- https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1cnnvd
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/cnnvd
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/cnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2020-35680cnnvd
- https://packetstormsecurity.com/files/162789/Gentoo-Linux-Security-Advisory-202105-12.htmlcnnvd
- https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/cnnvd
- https://security.gentoo.org/glsa/202105-12cnnvd
- https://vigilance.fr/vulnerability/OpenSMTPD-NULL-pointer-dereference-via-lka-filter-c-34442cnnvd
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