Samba: Denial of Service vulnerabilities

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200409-16 / Samba
Release Date	September 13, 2004
Latest Revision	September 13, 2004: 01
Impact	normal
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
net-fs/samba	< 3.0.7	>= 3.0.7, < 3.0	All supported architectures

Related bugreports: No related gentoo bugreports

Synopsis

Two Denial of Service vulnerabilities have been found and fixed in Samba.

2. Impact Information

Background

Samba is a freely available SMB/CIFS implementation which allows seamless interoperability of file and print services to other SMB/CIFS clients. smbd and nmbd are two daemons used by the Samba server.

Description

There is a defect in smbd's ASN.1 parsing. A bad packet received during the authentication request could throw newly-spawned smbd processes into an infinite loop (CAN-2004-0807). Another defect was found in nmbd's processing of mailslot packets, where a bad NetBIOS request could crash the nmbd process (CAN-2004-0808).

Impact

A remote attacker could send specially crafted packets to trigger both defects. The ASN.1 parsing issue can be exploited to exhaust all available memory on the Samba host, potentially denying all service to that server. The nmbd issue can be exploited to crash the nmbd process, resulting in a Denial of Service condition on the Samba server.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All Samba 3.x users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge sync
# emerge -pv ">=net-fs/samba-3.0.7"
# emerge ">=net-fs/samba-3.0.7"

4. References

Page updated September 13, 2004

Summary: This is a Gentoo Linux Security Advisory

Security Team
Contact Address

Donate to support our development efforts.