Debian DLA-1723-1 : cron security update

medium Nessus Plugin ID 123017

Synopsis

The remote Debian host is missing a security update.

Description

Various security problems have been discovered in Debian's CRON scheduler.

CVE-2017-9525

Fix group crontab to root escalation via the Debian package's postinst script as described by Alexander Peslyak (Solar Designer) in http://www.openwall.com/lists/oss-security/2017/06/08/3

CVE-2019-9704

DoS: Fix unchecked return of calloc(). Florian Weimer discovered that a missing check for the return value of calloc() could crash the daemon, which could be triggered by a very large crontab created by a user.

CVE-2019-9705

Enforce maximum crontab line count of 1000 to prevent a malicious user from creating an excessivly large crontab. The daemon will log a warning for existing files, and crontab(1) will refuse to create new ones.

CVE-2019-9706

A user reported a use-after-free condition in the cron daemon, leading to a possible denial of service scenario by crashing the daemon.

For Debian 8 'Jessie', these problems have been fixed in version 3.0pl1-127+deb8u2.

We recommend that you upgrade your cron packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Upgrade the affected cron package.

See Also

https://www.openwall.com/lists/oss-security/2017/06/08/3

https://lists.debian.org/debian-lts-announce/2019/03/msg00025.html

https://packages.debian.org/source/jessie/cron

Plugin Details

Severity: Medium

ID: 123017

File Name: debian_DLA-1723.nasl

Version: 1.5

Type: local

Agent: unix

Published: 3/25/2019

Updated: 6/13/2024

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.4

Vector: CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2017-9525

CVSS v3

Risk Factor: Medium

Base Score: 6.7

Temporal Score: 6

Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:8.0, p-cpe:/a:debian:debian_linux:cron

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/21/2019

Vulnerability Publication Date: 6/9/2017

Reference Information

CVE: CVE-2017-9525, CVE-2019-9704, CVE-2019-9705, CVE-2019-9706