--- title: "CVE-2020-10188\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-2020-10188?format=md keywords: index, follow --- # CVE-2020-10188 Publication date 6 March 2020 Last updated 29 September 2025 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **9.8 · Critical** [Score breakdown](https://ubuntu.com/security/CVE-2020-10188?format=md#impact-score) Toggle side navigation ## Description utility.c in telnetd in netkit telnet through 0.17 allows remote attackers to execute arbitrary code via short writes or urgent data, because of a buffer overflow involving the netclear and nextitem functions. [Read the notes from the security team](https://ubuntu.com/security/CVE-2020-10188?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | netkit-telnet-ssl | 26.04 LTS resolute | Needs evaluation | | 25.10 questing | Ignored end of life, was needs-triage | | 25.04 plucky | Ignored end of life, was needs-triage | | 24.10 oracular | Ignored end of life, was needs-triage | | 24.04 LTS noble | Needs evaluation | | 23.10 mantic | Ignored end of life, was needs-triage | | 23.04 lunar | Ignored end of life, was needs-triage | | 22.10 kinetic | Ignored end of life, was needs-triage | | 22.04 LTS jammy | Needs evaluation | | 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 | Needs evaluation | | 19.10 eoan | Ignored end of life | | 18.04 LTS bionic | Needs evaluation | | 16.04 LTS xenial | Needs evaluation | | 14.04 LTS trusty | Not in release | | inetutils | 26.04 LTS resolute | Not affected | | 25.10 questing | Not affected | | 25.04 plucky | Not affected | | 24.10 oracular | Not affected | | 24.04 LTS noble | Not affected | | 23.10 mantic | Not affected | | 23.04 lunar | Not affected | | 22.10 kinetic | Not affected | | 22.04 LTS jammy | Not affected | | 21.10 impish | Not affected | | 21.04 hirsute | Not affected | | 20.10 groovy | Not affected | | 20.04 LTS focal | Fixed 2:1.9.4-11ubuntu0.1 | | 18.04 LTS bionic | Fixed 2:1.9.4-3ubuntu0.1 | | 16.04 LTS xenial | Fixed 2:1.9.4-1ubuntu0.1~esm1 Ubuntu Pro | | 14.04 LTS trusty | Fixed 2:1.9.2-1ubuntu0.1~esm2 Ubuntu Pro | | netkit-telnet | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 25.04 plucky | Not in release | | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 23.10 mantic | Not in release | | 23.04 lunar | Not in release | | 22.10 kinetic | Not affected | | 22.04 LTS jammy | Not affected | | 21.10 impish | Not affected | | 21.04 hirsute | Ignored end of life | | 20.10 groovy | Ignored end of life | | 20.04 LTS focal | Not affected | | 19.10 eoan | Ignored end of life | | 18.04 LTS bionic | Not affected | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not affected | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) ### Get expanded security coverage with Ubuntu Pro Reduce your average CVE exposure time from 98 days to 1 day with expanded CVE patching, ten-years security maintenance and optional support for the full stack of open-source applications. Free for personal use. [Get Ubuntu Pro](https://ubuntu.com/pro) [30-day free trial](https://ubuntu.com/pro/free-trial) ## Notes --- ### [ccdm94](https://launchpad.net/~ccdm94) in netkit-telnet, this CVE was patched in 0.17-18woody2. See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=953477 for more information. ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 9.8 · Critical * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Network | | Attack complexity | Low | | Privileges required | None | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | High | | Integrity impact | High | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 9.8 · Critical | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-10188) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2020-10188) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2020-10188) * [Debian](https://security-tracker.debian.org/tracker/CVE-2020-10188) ### Related Ubuntu Security Notices (USN) + [USN-5048-1](https://usn.ubuntu.com/USN-5048-1) + Inetutils vulnerability + 19 August 2021 + [USN-5048-2](https://usn.ubuntu.com/USN-5048-2) + Inetutils vulnerability + 20 August 2021 + [USN-7781-1](https://usn.ubuntu.com/USN-7781-1) + Inetutils vulnerabilities + 28 September 2025 ### Other references * * *