______________________________________________________________________________ Caldera Systems, Inc. Security Advisory Subject: serious security problem in cron Advisory number: CSSA-1999:023.0 Issue date: 1999 August, 27 Cross reference: ______________________________________________________________________________
1. Problem Description
There is a serious security problem in the cron daemon. When a
program generates output, cron invokes the sendmail program as root
user, passing it as arguments whatever the user defined in the
MAILTO variable in his/her crontab.
Sendmail understands a number of potentially dangerous options.
When a normal user specifies these options, sendmail will
immediately drop all root privilege. Now, since cron invokes
sendmail as root user, sendmail will happily accept whatever
dangerous options it is given.
2. Vulnerable Versions
Systems : COL 2.2
Packages: previous to vixie-cron-3.0.1-19
3. Solutions
Workaround: none
The proper solution is to upgrade to the latest packages
rpm -U vixie-cron-3.0.1-19.i386.rpm
4. Location of Fixed Packages
The upgrade packages can be found on Caldera’s FTP site at:
ftp://ftp.calderasystems.com/pub/OpenLinux/updates/2.2/current/RPMS/
The corresponding source code package can be found at:
ftp://ftp.calderaystems.com/pub/OpenLinux/updates/2.2/current/SRPMS
5. Installing Fixed Packages
Upgrade the affected packages with the following commands:
rpm -U vixie-cron-3.0.1-19.i386.rpm
6. Verification
417cd4ff2a369d7383eec6a6793b99e7 vixie-cron-3.0.1-19.i386.rpm 80cf3430d59e7c5bfc24e75eac9a9f74 vixie-cron-3.0.1-19.src.rpm
7. References
This and other Caldera security resources are located at:
http://www.calderasystems.com/news/security/index.html
This security fix closes Caldera’s internal Problem Report
5086
8. Disclaimer
Caldera Systems, Inc. is not responsible for the misuse of any
of the information we provide on this website and/or through our
security advisories. Our advisories are a service to our customers
intended to promote secure installation and use of Caldera
OpenLinux.