Updated krb5 packages that fix one security issue are now available for Red Hat Enterprise Linux 5 and 6.
The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link associated with the description below.
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).
- It was found that kadmind's kpasswd service did not perform any validation on incoming network packets, causing it to reply to all requests. A remote attacker could use this flaw to send spoofed packets to a kpasswd service that appear to come from kadmind on a different server, causing the services to keep replying packets to each other, consuming network bandwidth and CPU.
All krb5 users should upgrade to these updated packages, which contain a backported patch to correct this issue. After installing the updated packages, the krb5kdc and kadmind daemons will be restarted automatically