Updated Kerberos (krb5) packages that correct multiple security issues are now available.
Kerberos is a networked authentication system that uses a trusted third party (a KDC) to authenticate clients and servers to each other.
Note that some of these issues have already been fixed in Fedora Core 1. Please refer to previous advisories for details.
2. Relevant releases/architectures:
Red Hat Linux 7.3 - i386 Red Hat Linux 9 - i386 Fedora Core 1 - i386
3. Problem description:
Several buffer overflows were possible for all Kerberos versions up to and including 1.3.3 in the krb5_aname_to_localname library function. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0523 to this issue.
Several double-free bugs were found in the Kerberos 5 KDC and libraries. A remote attacker could potentially exploit these flaws to execuate arbitrary code. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the names CAN-2004-0642 and CAN-2004-0643 to these issues.
A double-free bug was also found in the krb524 server. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0772 to this issue.
An infinite loop bug was found in the Kerberos 5 ASN.1 decoder library. A remote attacker may be able to trigger this flaw and cause a denial of service. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0644 to this issue.
A heap based buffer overflow bug was found in the administration library of Kerberos 1.3.5 and earlier. This bug could allow an authenticated remote attacker to execute arbitrary commands on a realm's master Kerberos KDC. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-1189 to this issue.
Additionally a temporary file bug was found in the Kerberos krb5-send-pr program. It is possible that an attacker could create a temporary file that would allow an arbitrary file to be overwritten which the victim has write access to. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0971 to this issue.
The krb5-workstation package includes a Kerberos-aware telnet client. Two buffer overflow flaws were discovered in the way the telnet client handles messages from a server. An attacker may be able to execute arbitrary code on a victim's machine if the victim can be tricked into connecting to a malicious telnet server. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the names CAN-2005-0468 and CAN-2005-0469 to these issues.
All users of krb5 should upgrade to these updated packages, which contain backported security patches to resolve these issues.
Before applying this update, make sure all previously released errata relevant to your system have been applied.
To update all RPMs for your particular architecture, run:
rpm -Fvh [filenames]
where [filenames] is a list of the RPMs you wish to upgrade. Only those RPMs which are currently installed will be updated. Those RPMs which are not installed but included in the list will not be updated. Note that you can also use wildcards (*.rpm) if your current directory *only* contains the desired RPMs.
Please note that this update is also available via yum and apt. Many people find this an easier way to apply updates. To use yum issue:
or to use apt:
apt-get update; apt-get upgrade
This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. This assumes that you have yum or apt-get configured for obtaining Fedora Legacy content. Please visit http://www.fedoralegacy.org/docs for directions on how to configure yum and apt-get.