Debian Security Advisory
DLA-1723-1 cron -- LTS security update
- Date Reported:
- 21 Mar 2019
- Affected Packages:
- cron
- Vulnerable:
- Yes
- Security database references:
- In the Debian bugtracking system: Bug 809167.
In Mitre's CVE dictionary: CVE-2017-9525, CVE-2019-9704, CVE-2019-9705, CVE-2019-9706. - More information:
-
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.
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
- CVE-2017-9525