Scientific Linux Security Update : sssd on SL6.x i386/x86_64

Medium Nessus Plugin ID 86846


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


It was found that SSSD's Privilege Attribute Certificate (PAC) responder plug-in would leak a small amount of memory on each authentication request. A remote attacker could potentially use this flaw to exhaust all available memory on the system by making repeated requests to a Kerberized daemon application configured to authenticate using the PAC responder plug-in. (CVE-2015-5292)

This update also fixes the following bugs :

- Previously, SSSD did not correctly handle sudo rules that applied to groups with names containing special characters, such as the '(' opening parenthesis sign.
Consequently, SSSD skipped such sudo rules. The internal sysdb search has been modified to escape special characters when searching for objects to which sudo rules apply. As a result, SSSD applies the described sudo rules as expected.

- Prior to this update, SSSD did not correctly handle group names containing special Lightweight Directory Access Protocol (LDAP) characters, such as the '(' or ')' parenthesis signs. When a group name contained one or more such characters, the internal cache cleanup operation failed with an I/O error. With this update, LDAP special characters in the Distinguished Name (DN) of a cache entry are escaped before the cleanup operation starts. As a result, the cleanup operation completes successfully in the described situation.

- Applications performing Kerberos authentication previously increased the memory footprint of the Kerberos plug-in that parses the Privilege Attribute Certificate (PAC) information. The plug-in has been updated to free the memory it allocates, thus fixing this bug.

- Previously, when malformed POSIX attributes were defined in an Active Directory (AD) LDAP server, SSSD unexpectedly switched to offline mode. This update relaxes certain checks for AD POSIX attribute validity.
As a result, SSSD now works as expected even when malformed POSIX attributes are present in AD and no longer enters offline mode in the described situation.

After installing the update, the sssd service will be restarted automatically. Additionally, all running applications using the PAC responder plug-in must be restarted for the changes to take effect.


Update the affected packages.

See Also

Plugin Details

Severity: Medium

ID: 86846

File Name: sl_20151110_sssd_on_SL6_x.nasl

Version: $Revision: 2.1 $

Type: local

Agent: unix

Published: 2015/11/11

Modified: 2015/11/11

Dependencies: 12634

Risk Information

Risk Factor: Medium


Base Score: 6.8

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

Vulnerability Information

CPE: x-cpe:/o:fermilab:scientific_linux

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

Patch Publication Date: 2015/11/10

Reference Information

CVE: CVE-2015-5292