[USN-5259-2] Cron vulnerabilities


Ubuntu Security Notice USN-5259-2 May 06, 2022
cron vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 18.04 LTS
Summary:
Several security issues were fixed in Cron.
Software Description: – cron: process scheduling daemon
Details:
USN-5259-1 fixed several vulnerabilities in Cron. This update provides the corresponding update for Ubuntu 18.04 LTS.
Original advisory details:
 It was discovered that the postinst maintainer script in Cron unsafely  handled file permissions during package install or update operations.  An attacker could possibly use this issue to perform a privilege  escalation attack. (CVE-2017-9525)
 Florian Weimer discovered that Cron incorrectly handled certain memory  operations during crontab file creation. An attacker could possibly use  this issue to cause a denial of service. (CVE-2019-9704)
 It was discovered that Cron incorrectly handled user input during crontab  file creation. An attacker could possibly use this issue to cause a denial  of service. (CVE-2019-9705)
 It was discovered that Cron contained a use-after-free vulnerability in  its force_rescan_user function. An attacker could possibly use this issue  to cause a denial of service. (CVE-2019-9706)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 18.04 LTS:   cron                            3.0pl1-128.1ubuntu1.1
In general, a standard system update will make all the necessary changes.
References:   ubuntu.com/security/notices/USN-5259-2   ubuntu.com/security/notices/USN-5259-1   CVE-2017-9525, CVE-2019-9704, CVE-2019-9705, CVE-2019-9706
Package Information:   launchpad.net/ubuntu/+source/cron/3.0pl1-128.1ubuntu1.1