What is CVE-2017-20002?

CVE-2017-20002 is a high-severity vulnerability in Debian Linux, classified under Improper Privilege Management. CVSS score: 7.8/10. Published 2021-03-17.

How severe is CVE-2017-20002?

High severity. CVSS v3 base score is 7.8 out of 10.

Privilege escalation in Debian Linux

CVE-2017-20002

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.

Vulnerability class: Privilege Escalation

Published 2021-03-17 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (33.2th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Debian Linux — versions 9.0
Debian Shadow — versions 4.4

Weakness classification (CWE)

CWE-269 — Improper Privilege Management

References

bugs.debian.org/cgi-bin/bugreport.cgi (Mailing List, Vendor Advisory)
bugs.debian.org/cgi-bin/bugreport.cgi (Exploit, Mailing List, Vendor Advisory)
lists.debian.org/debian-lts-announce/2021/03/msg00020.html (Vendor Advisory, mailing-list, Mailing List)

Frequently asked questions

What is CVE-2017-20002?: CVE-2017-20002 is a high-severity vulnerability in Debian Linux, classified under Improper Privilege Management. CVSS score: 7.8/10. Published 2021-03-17.
How severe is CVE-2017-20002?: High severity. CVSS v3 base score is 7.8 out of 10.