CVE-2020-35680: Null Pointer Dereference
First published: Thu Dec 24 2020(Updated: )
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.
Credit: cve@mitre.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Opensmtpd Opensmtpd | <6.8.0 | |
| Opensmtpd Opensmtpd | =6.8.0 | |
| Opensmtpd Opensmtpd | =6.8.0-patch1-rc1 | |
| Fedoraproject Fedora | =32 | |
| Fedoraproject Fedora | =33 |
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Reference Links
- https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.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/
- https://security.gentoo.org/glsa/202105-12
- https://www.mail-archive.com/misc@opensmtpd.org/msg05188.html
- https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/
Frequently Asked Questions
What is CVE-2020-35680?
CVE-2020-35680 is a vulnerability in OpenSMTPD before 6.8.0p1 that can allow remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted pattern of client activity.
How does CVE-2020-35680 impact OpenSMTPD?
CVE-2020-35680 can cause a denial of service in OpenSMTPD, leading to a crash of the daemon.
What is the severity of CVE-2020-35680?
The severity of CVE-2020-35680 is high, with a CVSS score of 7.5.
Which versions of OpenSMTPD are affected by CVE-2020-35680?
OpenSMTPD versions before 6.8.0p1 are affected by CVE-2020-35680.
How can I fix CVE-2020-35680?
To fix CVE-2020-35680, it is recommended to update to OpenSMTPD 6.8.0p1 or later.
- collector/nvd-index
- agent/weakness
- agent/event
- agent/references
- agent/severity
- agent/author
- agent/description
- agent/type
- agent/last-modified-date
- agent/softwarecombine
- agent/first-publish-date
- agent/remedy
- agent/tags
- collector/mitre-cve
- source/MITRE
- vendor/opensmtpd
- canonical/opensmtpd opensmtpd
- version/opensmtpd opensmtpd/6.8.0
- version/opensmtpd opensmtpd/6.8.0-patch1-rc1
- vendor/fedoraproject
- canonical/fedoraproject fedora
- version/fedoraproject fedora/32
- version/fedoraproject fedora/33