CVE-2017-20002

Name: CVE-2017-20002
Creator: NVD / NIST
Published: 2021-03-17T06:15:12.107+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.40%

Last modified Jun 17, 2026

CVE-2017-20002 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. The Debian shadow package before 1:4.5-1 for Shadow incorrectly lists pts/0 and pts/1 as physical terminals in /etc/securetty. This allows local users to login as password-less users even if they are connected by non-physical means such as SSH (hence bypassing PAM's nullok_secure configuration). EPSS estimates a 0.40% chance of exploitation in the next 30 days.

Description

The Debian shadow package before 1:4.5-1 for Shadow incorrectly lists pts/0 and pts/1 as physical terminals in /etc/securetty. This allows local users to login as password-less users even if they are connected by non-physical means such as SSH (hence bypassing PAM's nullok_secure configuration). This notably affects environments such as virtual machines automatically generated with a default blank root password, allowing all local users to escalate privileges.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

0.40%

32.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-269

Affected Software

Vendor	Product	Versions
Debian	Shadow	4.4
Debian	Debian Linux	9.0

References

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=877374Mailing List, Vendor Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914957Exploit, Mailing List, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00020.htmlMailing List, Vendor Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=877374Mailing List, Vendor Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914957Exploit, Mailing List, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2021/03/msg00020.htmlMailing List, Vendor Advisory

Timeline

Published: Mar 17, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-20002?

How severe is CVE-2017-20002?

CVE-2017-20002 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2017-20002?

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-2017-20002?

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

Scan your code now

Source: NVD / NIST