Updated samba packages that fix two denial of service vulnerabilities are now available. [Updated 23rd September 2004] Packages have been updated to include the ppc64 packages which were left out of the initial errata.
Samba provides file and printer sharing services to SMB/CIFS clients. The Samba team has discovered a denial of service bug in the smbd daemon. A defect in smbd's ASN.1 parsing allows an attacker to send a specially crafted packet during the authentication request which will send the newly spawned smbd process into an infinite loop. Given enough of these packets, it is possible to exhaust the available memory on the server. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0807 to this issue. Additionally the Samba team has also discovered a denial of service bug in the nmbd daemon. It is possible that an attacker could send a specially crafted UDP packet which could allow the attacker to anonymously crash nmbd. This issue only affects nmbd daemons which are configured to process domain logons. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0808 to this issue. Users of Samba should upgrade to these updated packages, which contain an upgrade to Samba-3.0.7, which is not vulnerable to these issues.