Multiple remote buffer overflow vulnerabilities have been reported for Samba and Samba-TNG. Although unspecified, it is likely that these issues are exploitable by an attacker to execute arbitrary code. All code executed in this manner would be run with the privileges of Samba, typically root. These vulnerabilities are reported to affect Samba 2.2.8 and Samba-TNG 0.3.1. ** Reports suggest that an automated attack utility may be actively exploiting this vulnerability likely through a bruteforce attack. Although unconfirmed, it may be possible that this may be a worm. The attack utility has been reported to create several files and drop a trojaned version of the sshd. Reportedly, the trojaned SSH daemon listens for connections on port 44444. This attack utility was only observed to be attacking FreeBSD systems however, it is likely that other systems are also affected.
Block external access at the network boundary, unless external parties require service.
Restrict remote access to Samba-based services from all but trusted hosts. This will limit an attacker's ability to exploit this vulnerability.
Run all software as a nonprivileged user with minimal access rights.
Where possible, run the Samba server with the least privileges required to function. This will limit the consequences of an attacker gaining the ability to execute arbitrary code.
Modify default ACL settings.
Unless anonymous access is specifically required, modify Samba's access control list to prevent connections from anonymous users.
Implement multiple redundant layers of security.
The exploitation of vulnerabilities to execute arbitrary code may be hindered through the use of various memory protection schemes. Where possible, implement the use of non-executable and randomly mapped memory pages.
Disable any services that are not needed.
Unless the use of Samba is explicitly required, disable its use completely.
Samba 2.2.8a has been released which addresses these issues. Samba is currently developing patches which will specifically address the problems in version 2.2.7a and 2.0.10. Users are advised to upgrade as soon as possible. Slackware has released a security advisory (2003-04-08) containing fixes which address this issue. Debian has released a security advisory (DSA 280-1) containing fixes which address this issue. OpenPKG has released a security advisory (OpenPKG-SA-2003.028) containing fixes which address this issue. Mandrake has released a security advisory (MDKSA-2003:044) containing fixes which address this issue. FreeBSD has released a security note (FreeBSD-SN-03:01) which contains updated ports information. Further information can be found in the attached advisory. Immunix has released a security advisory (IMNX-2003-7+-006-01) which contains fixes which address this issue for Samba 2.0.10. Users are advised to upgrade as soon as possible. Red Hat has revised its advisory (RHSA-2003:137-02). See referenced advisory for new fix details. Gentoo Linux has released an advisory. Users who have installed net-fs/samba are advised to upgrade to samba-2.2.8a by issuing the following commands: emerge sync emerge samba emerge clean HP has released an advisory HPSBUX0304-254. HP has stated that new smbd binaries (smbd.11.00.r1.gz) are available at the following locations. Further information is available in the referenced advisory: ftp://samba:firstname.lastname@example.org/ ftp://samba:email@example.com/ ftp hprc.external.hp.com Veritas has determined that various ServPoint NAS releases are affected by this vulnerability. Patches are currently being developed. Users are advised to contact the vendor for further information regarding how to obtain fixes.