Debian: DLA-1723-1 Moderate: Cron Scheduler Security Issues

CVE-2017-9525

Fix group crontab to root escalation via the Debian package's
postinst script as described by Alexander Peslyak (Solar Designer) in
https://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.