---
title: "CVE-2020-35680\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2020-35680?format=md
keywords: index, follow
---

# CVE-2020-35680

Publication date 24 December 2020

Last updated 11 July 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2020-35680?format=md#impact-score)

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## 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.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| opensmtpd | 26.04 LTS resolute | Vulnerable |
| 25.10 questing | Ignored end of life, was needed |
| 25.04 plucky | Ignored end of life, was needed |
| 24.10 oracular | Ignored end of life, was needed |
| 24.04 LTS noble | Vulnerable |
| 23.10 mantic | Ignored end of life, was needed |
| 23.04 lunar | Ignored end of life, was needed |
| 22.10 kinetic | Ignored end of life, was needed |
| 22.04 LTS jammy | Vulnerable |
| 21.10 impish | Ignored end of life |
| 21.04 hirsute | Ignored end of life |
| 20.10 groovy | Ignored end of life |
| 20.04 LTS focal | Vulnerable |
| 18.04 LTS bionic | Not affected |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Needs evaluation |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | None |
  | Integrity impact | None |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-35680)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2020-35680)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2020-35680)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2020-35680)

### Other references

* <https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1>
* <https://www.mail-archive.com/misc@opensmtpd.org/msg05188.html>
* <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://www.cve.org/CVERecord?id=CVE-2020-35680>