Scientific Linux Security Update : vixie-cron on SL5.x i386/x86_64 (20120221)

low Nessus Plugin ID 61273

Synopsis

The remote Scientific Linux host is missing one or more security updates.

Description

The vixie-cron package contains the Vixie version of cron. Cron is a standard UNIX daemon that runs specified programs at scheduled times.
The vixie-cron package adds improved security and more powerful configuration options to the standard version of cron.

A race condition was found in the way the crontab program performed file time stamp updates on a temporary file created when editing a user crontab file. A local attacker could use this flaw to change the modification time of arbitrary system files via a symbolic link attack. (CVE-2010-0424)

This update also fixes the following bugs :

- Cron jobs of users with home directories mounted on a Lightweight Directory Access Protocol (LDAP) server or Network File System (NFS) were often refused because jobs were marked as orphaned (typically due to a temporary NSS lookup failure, when NIS and LDAP servers were unreachable). With this update, a database of orphans is created, and cron jobs are performed as expected.

- Previously, cron did not log any errors if a cron job file located in the /etc/cron.d/ directory contained invalid entries. An upstream patch has been applied to address this problem and invalid entries in the cron job files now produce warning messages.

- Previously, the '@reboot' crontab macro incorrectly ran jobs when the crond daemon was restarted. If the user used the macro on multiple machines, all entries with the '@reboot' option were executed every time the crond daemon was restarted. With this update, jobs are executed only when the machine is rebooted.

- The crontab utility is now compiled as a position-independent executable (PIE), which enhances the security of the system.

- When the parent crond daemon was stopped, but a child crond daemon was running (executing a program), the 'service crond status' command incorrectly reported that crond was running. The source code has been modified, and the 'service crond status' command now correctly reports that crond is stopped.

- According to the pam(8) manual page, the cron daemon, crond, supports access control with PAM (Pluggable Authentication Module). However, the PAM configuration file for crond did not export environment variables correctly and, consequently, setting PAM variables via cron did not work. This update includes a corrected /etc/pam.d/crond file that exports environment variables correctly. Setting pam variables via cron now works as documented in the pam(8) manual page.

- Previously, the mcstransd daemon modified labels for the crond daemon. When the crond daemon attempted to use the modified label and mcstransd was not running, crond used an incorrect label. Consequently, Security-Enhanced Linux (SELinux) denials filled up the cron log, no jobs were executed, and crond had to be restarted. With this update, both mcstransd and crond use raw SELinux labels, which prevents the problem.

- Previously, the crontab(1) and cron(8) manual pages contained multiple typographical errors. This update fixes those errors.

In addition, this update adds the following enhancement :

- Previously, the crontab utility did not use the Pluggable Authentication Module (PAM) for verification of users. As a consequence, a user could access crontab even if access had been restricted (usually by being denied in the access.conf file). With this update, crontab returns an error message that the user is not allowed to access crontab because of PAM configuration.

All vixie-cron users should upgrade to this updated package, which resolves these issues and adds this enhancement.

Solution

Update the affected vixie-cron and / or vixie-cron-debuginfo packages.

See Also

http://www.nessus.org/u?c64f48eb

Plugin Details

Severity: Low

ID: 61273

File Name: sl_20120221_vixie_cron_on_SL5_x.nasl

Version: 1.6

Type: local

Agent: unix

Published: 8/1/2012

Updated: 1/14/2021

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.2

CVSS v2

Risk Factor: Low

Base Score: 3.3

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

Vulnerability Information

CPE: p-cpe:/a:fermilab:scientific_linux:vixie-cron, p-cpe:/a:fermilab:scientific_linux:vixie-cron-debuginfo, x-cpe:/o:fermilab:scientific_linux

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Patch Publication Date: 2/21/2012

Vulnerability Publication Date: 2/25/2010

Reference Information

CVE: CVE-2010-0424

CWE: 59