- -------------------------------------------------------------------------
Debian LTS Advisory DLA-2596-1                debian-lts@lists.debian.org
https://www.debian.org/lts/security/                      Sylvain Beucler
March 17, 2021                                https://wiki.debian.org/LTS
- -------------------------------------------------------------------------

Package        : shadow
Version        : 1:4.4-4.1+deb9u1
CVE ID         : CVE-2017-12424 CVE-2017-20002
Debian Bug     : 756630 914957

Several vulnerabilities were discovered in the shadow suite of login
tools. An attacker may escalate privileges in specific configurations.

CVE-2017-20002

    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. It should be noted however that
    /etc/securetty will be dropped in Debian 11/bullseye.

CVE-2017-12424

    The newusers tool could be made to manipulate internal data
    structures in ways unintended by the authors. Malformed input may
    lead to crashes (with a buffer overflow or other memory
    corruption) or other unspecified behaviors. This crosses a
    privilege boundary in, for example, certain web-hosting
    environments in which a Control Panel allows an unprivileged user
    account to create subaccounts.

For Debian 9 stretch, these problems have been fixed in version
1:4.4-4.1+deb9u1.

We recommend that you upgrade your shadow packages.

For the detailed security status of shadow please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/shadow

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS

Debian LTS: DLA-2596-1: shadow security update

March 17, 2021
Several vulnerabilities were discovered in the shadow suite of login tools

Summary

CVE-2017-20002

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. It should be noted however that
/etc/securetty will be dropped in Debian 11/bullseye.

CVE-2017-12424

The newusers tool could be made to manipulate internal data
structures in ways unintended by the authors. Malformed input may
lead to crashes (with a buffer overflow or other memory
corruption) or other unspecified behaviors. This crosses a
privilege boundary in, for example, certain web-hosting
environments in which a Control Panel allows an unprivileged user
account to create subaccounts.

For Debian 9 stretch, these problems have been fixed in version
1:4.4-4.1+deb9u1.

We recommend that you upgrade your shadow packages.

For the detailed security status of shadow please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/shadow

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS


Severity
Package : shadow
Version : 1:4.4-4.1+deb9u1
CVE ID : CVE-2017-12424 CVE-2017-20002
Debian Bug : 756630 914957

Related News

23.Tablet Connections Esm H320
2 - 3 min read
The release of Ubuntu 24.04 LTS , also known as Noble Numbat, brings various security enhancements and exciting new features . These improvements
4.Lock AbstractDigital Esm H320
2 - 3 min read
Tails 6.2 is a new Linux distribution release that expands its multilingual support and improves security features. The distribution is a
19.Laptop Bed Esm H320
2 - 3 min read
AlmaLinux 9.4 beta has been released and provides compelling reasons to consider it for desktop usage. While AlmaLinux is primarily known as a
32.Lock Code Circular Esm H320
2 - 3 min read
Linux admins and security practitioners face significant challenges in keeping their Linux systems secure amidst the constant threat of kernel bugs.
1.Penguin Landscape Esm H320
2 - 3 min read
A significant security threat, known as the Spectre v2 exploit, has been observed targeting Linux systems running on modern Intel processors. Let's
10.FingerPrint Locks Esm H320
2 - 3 min read
The recent release of I2P 2.5.0 , an anonymous P2P network that protects against online censorship, surveillance, and monitoring, has brought a slew
24.Key Code Esm H320
2 - 3 min read
The Akira ransomware group has extorted approximately $42 million from over 250 victims since January 1, 2024. The group initially focused on
5.ShakingHands Esm H320
2 - 3 min read
At The Linux Foundation's Open Source Summit North America , Linus Torvalds, the creator of Linux, discussed various topics related to Linux
Sign Up

Get the Latest News & Insights

Sign up to get the latest security news affecting Linux and open source delivered straight to your inbox.

© 2024 Guardian Digital, Inc All Rights Reserved