Scientific Linux Security Update : krb5-appl on SL6.x i386/x86_64

Critical Nessus Plugin ID 61213


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


The krb5-appl packages provide Kerberos-aware telnet, ftp, rcp, rsh, and rlogin clients and servers. Kerberos is a network authentication system which allows clients and servers to authenticate to each other using symmetric encryption and a trusted third party, the Key Distribution Center (KDC).

A buffer overflow flaw was found in the MIT krb5 telnet daemon (telnetd). A remote attacker who can access the telnet port of a target machine could use this flaw to execute arbitrary code as root.

Note that the krb5 telnet daemon is not enabled by default in any version of Scientific Linux. In addition, the default firewall rules block remote access to the telnet port. This flaw does not affect the telnet daemon distributed in the telnet-server package.

For users who have installed the krb5-appl-servers package, have enabled the krb5 telnet daemon, and have it accessible remotely, this update should be applied immediately.

All krb5-appl-server users should upgrade to these updated packages, which contain a backported patch to correct this issue.


Update the affected krb5-appl-clients, krb5-appl-debuginfo and / or krb5-appl-servers packages.

See Also

Plugin Details

Severity: Critical

ID: 61213

File Name: sl_20111227_krb5_appl_on_SL6_x.nasl

Version: $Revision: 1.6 $

Type: local

Agent: unix

Published: 2012/08/01

Modified: 2014/06/16

Dependencies: 12634

Risk Information

Risk Factor: Critical


Base Score: 10

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2011/12/27

Exploitable With

Core Impact

Metasploit (Linux BSD-derived Telnet Service Encryption Key ID Buffer Overflow)

ExploitHub (EH-11-760)

Reference Information

CVE: CVE-2011-4862