CVE-2020-10188

Name: CVE-2020-10188
Creator: NVD / NIST
Published: 2020-03-06T15:15:14.02+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 74.51%

Last modified Jun 17, 2026

CVE-2020-10188 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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.. EPSS estimates a 74.51% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

74.51%

99.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-120

Affected Software

Vendor	Product	Versions
Netkit Telnet Project	Netkit Telnet	<= 0.17
Fedoraproject	Fedora	30
Fedoraproject	Fedora	31
Fedoraproject	Fedora	32
Debian	Debian Linux	8.0
Debian	Debian Linux	9.0
Arista	Eos	<= 4.20.15
Arista	Eos	>= 4.21.0, <= 4.21.10m
Arista	Eos	>= 4.22, <= 4.22.4m
Arista	Eos	>= 4.23, <= 4.23.3m
Arista	Eos	4.24.0f
Oracle	Communications Performance Intelligence Center	10.4.0.2
Juniper	Junos	12.3
Juniper	Junos	12.3r12
Juniper	Junos	12.3x48
Juniper	Junos	12.3x50
Juniper	Junos	15.1
Juniper	Junos	15.1x49
Juniper	Junos	15.1x49-d30
Juniper	Junos	15.1x49-d60
Juniper	Junos	15.1x49-d140
Juniper	Junos	15.1x49-d150
Juniper	Junos	15.1x49-d160
Juniper	Junos	16.1
Juniper	Junos	17.2
Juniper	Junos	17.2x75
Juniper	Junos	17.3
Juniper	Junos	17.4
Juniper	Junos	18.1
Juniper	Junos	18.2
Juniper	Junos	18.2x75
Juniper	Junos	18.2x75-d10
Juniper	Junos	18.2x75-d30
Juniper	Junos	18.3
Juniper	Junos	18.4
Juniper	Junos	19.1
Juniper	Junos	19.2
Juniper	Junos	19.3
Juniper	Junos	19.4
Juniper	Junos	20.1

References

https://appgateresearch.blogspot.com/2020/02/bravestarr-fedora-31-netkit-telnetd_28.htmlThird Party Advisory
https://github.com/krb5/krb5-appl/blob/d00cd671dfe945791b33d4f1f6a5c57ae1667ef8/telnet/telnetd/utility.c#L205-L216Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/05/msg00012.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/08/msg00038.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7FMTRRQTYKWZD2GMXX3GLZV46OLPCLVK/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HLU6FL24BSQQEB2SJC26NLJ2MANQDA7M/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K3VJ6V2Z3JRNJOBVHSOPMAC76PSSKG6A/
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-telnetd-EFJrEzPxThird Party Advisory
https://www.arista.com/en/support/advisories-notices/security-advisories/10702-security-advisory-48Third Party Advisory
https://www.oracle.com/security-alerts/cpuApr2021.htmlPatch, Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/01/20/8
https://appgateresearch.blogspot.com/2020/02/bravestarr-fedora-31-netkit-telnetd_28.htmlThird Party Advisory
https://github.com/krb5/krb5-appl/blob/d00cd671dfe945791b33d4f1f6a5c57ae1667ef8/telnet/telnetd/utility.c#L205-L216Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/05/msg00012.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/08/msg00038.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7FMTRRQTYKWZD2GMXX3GLZV46OLPCLVK/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HLU6FL24BSQQEB2SJC26NLJ2MANQDA7M/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/K3VJ6V2Z3JRNJOBVHSOPMAC76PSSKG6A/
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-telnetd-EFJrEzPxThird Party Advisory
https://www.arista.com/en/support/advisories-notices/security-advisories/10702-security-advisory-48Third Party Advisory
https://www.oracle.com/security-alerts/cpuApr2021.htmlPatch, Third Party Advisory

Timeline

Published: Mar 6, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-10188?

How severe is CVE-2020-10188?

CVE-2020-10188 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 74.51% probability of exploitation in the next 30 days.

How do I fix CVE-2020-10188?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-10188?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST