PT-2018-3767 · Debian+1 · Debian Shadow+1

Published 2017-09-06 · Updated 2021-06-07 · CVE-2017-20002

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Debian shadow package versions prior to 1:4.5-1

Description The issue is related to the incorrect listing of pts/0 and pts/1 as physical terminals in /etc/securetty, which allows local users to login as password-less users even if they are connected by non-physical means such as SSH. This bypasses PAM's nullok secure configuration and notably affects environments like virtual machines with default blank root passwords, enabling local users to escalate privileges.

Recommendations For Debian shadow package versions prior to 1:4.5-1, update to version 1:4.5-1 or later to resolve the issue. As a temporary workaround, consider modifying the /etc/securetty file to correctly reflect physical terminals, thereby preventing password-less login via non-physical means. Restrict access to virtual machines with default blank root passwords to minimize the risk of exploitation.

Exploit

Fix

Improper Privilege Management

Weakness Enumeration

CWE-269

Related Identifiers

ALT-PU-2017-2150

BDU:2021-05845

CVE-2017-20002

DLA-2596-1

Affected Products

Alt Linux

Debian Shadow

References · 25

• 🔥 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914957 · Exploit
• https://security-tracker.debian.org/tracker/DLA-2596-1 · Vendor Advisory
• https://safe-surf.ru/specialists/bulletins-nkcki/674665 · Security Note
• https://errata.altlinux.org/ALT-PU-2017-2150 · Vendor Advisory
• https://lists.debian.org/debian-lts-announce/2021/03/msg00020.html · Vendor Advisory
• https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=877374 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-12424 · Security Note
• https://ubuntu.com/security/CVE-2017-20002 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2017-20002 · Security Note
• https://bdu.fstec.ru/vul/2021-05844 · Security Note
• https://wiki.astralinux.ru/astra-linux-se81-bulletin-20211019SE81 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2017-20002 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2017-20002 · Vendor Advisory
• https://osv.dev/vulnerability/DLA-2596-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2017-20002 · Security Note