Published:
26 July 1999
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-1999.100 -- Samba 2.0.5 security fixes 27 July 1999 =========================================================================== The Samba Team has released the following advisory concerning security vulnerabilities in Samba versions prior to 2.0.5 available for various platforms. - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Samba 2.0.5 has just been released. This fixes a number of bugs, including 3 security holes. The security holes were discovered by Olaf Kirch (okir@caldera.de) who performed a security audit on Samba for Caldera. The security holes were: 1) a denial of service attack on nmbd (the netbios name service daemon). The attack made nmbd spin using up CPU resources until it was killed. 2) A buffer overflow in the message service in smbd. This was exploitable if the system administrator had set the "message command" option in smb.conf. This option is not set by default. 3) A race condition in smbmnt which would allow a user to mount at arbitrary points in the filesystem. This could only be exploited if smbmnt is setuid, which it is not by default. While no instances of these holes being exploited are known, it would not be wise to just ignore these issues. A motivated attacker could almost certainly produce an exploit very quickly. New release - - ----------- The Samba 2.0.5 release fixes these and other bugs. See http://www.samba.org/ for the release notes and download. The Samba 2.0.5 release has the following MD5 checksum 9fa63ff151ae697648020df37464eca9 b samba-2.0.5.tar.gz Workarounds - - ----------- If you cannot upgrade to version 2.0.5 then we recommend the following action as temporary workarounds: 1) remove the "message command" option from smb.conf if you have set it. 2) remove the setuid bit from smbmnt if it is set (use "chmod u-s smbmnt") 3) if nmbd starts using large amounts of CPU then kill and restart it. Credits - - ------- Thanks to Olaf Kirch and Caldera for their thorough security audit and help in producing a suitable fix. - -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv iQCVAwUBN5UxPWNSlURsK/StAQFWtQQAmGC1XjOdsqgLIHMZwPKvwk/dNP8biUlC 1p7PN9cw+oTWeQMtjN9xX+UAAKK7wKzCL+hZiFigYWVGIWItC6oVJbGVqIqa2Ik1 ThDi3oZ5411x1Hkadb+Ox9Xz8ZAmKw3euN6mnD1MbmMiZnnndnxTl9cneqWBkwS5 fJp12Qf2fCc= =O11u - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to use any or all of this information is the responsibility of each user or organisation, and should be done so in accordance with site policies and procedures. NOTE: This is only the original release of the security bulletin. It will not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the original authors to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/Information/advisories.html If you believe that your system has been compromised, contact AusCERT or your representative in FIRST (Forum of Incident Response and Security Teams). Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for emergencies. -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key iQCVAwUBN+du2Sh9+71yA2DNAQFOsAP/QVmx055oof4TyxJjiFd7ZM1KbyHVtjXG UCd8KySQVglESd5auO4u1c+HFVaG9HJ+Q/w2b58rkJXuW4jHBlcLI/QADtPQqlEJ jjbhCPFDxrcE/VHUzeyTR4ef23uN8vVTuJrN920kffr3xT3CMCC+pNsje40UKDJN 6lDPgDmvCf4= =+49a -----END PGP SIGNATURE-----