Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2003.0141 -- Snort Vulnerability Advisory [SNORT-2003-001] 04 March 2003 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Snort Operating System: UNIX Impact: Root Compromise Access Required: Remote Ref: ESB-2003.0137 - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Snort Vulnerability Advisory [SNORT-2003-001] Date: 2003-03-03 Affected Snort Versions: Any version starting with version 1.8 to those before 2003-03-03 1PM/ US/Eastern including 1.9.0 and CVS HEAD (Snort 2.0beta) Synopsis: A buffer overflow has been found in the snort RPC normalization routines by ISS X-Force. This can cause snort to execute arbitrary code embedded within sniffed network packets. This preprocessor is enabled by default. Snort 1.9.1 has been released to resolve this issue. For users using CVS HEAD, a fix has been committed to the source tree. Mitigation: If you are in an environment that can not upgrade snort immediately, comment out the line in your snort.conf that begins: preprocessor rpc_decode and replace it with # preprocessor rpc_decode Details: When the rpc decoder normalizes fragmented RPC records, it incorrectly checks the lengths of what is being normalized against the current packet size. The rpc decoder in Snort 1.9.1 and above contains new alert options that can be used to help detect this attack Option Default State alert_fragments INACTIVE alert_large_fragments ACTIVE alert_incomplete ACTIVE alert_multiple_requests ACTIVE The first option will alert on any rpc fragmented record it finds. Large fragments will alert when the reassembled fragment record will exceed the current packet length. The incomplete record will alert when there is a partial record found. The alert_multiple_requests will alert when we find more than one RPC request per packet ( or reassembled packet ). Download Locations: Sourcefire has acquired additional bandwidth and hosting to aid users wishing to upgrade their Snort implementation. Binaries are currently not available, this is a source release only at this time. As new binaries become available they will be added to the site. Source code: http://www.snort.org/dl/snort-1.9.1.tar.gz GPG Signatures: http://www.snort.org/dl/snort-1.9.1.tar.gz.asc CVS HEAD (Snort 2.0beta) has been fixed as well. - - -- Martin Roesch - Founder/CTO, Sourcefire Inc. - (410)290-1616 Sourcefire: Snort-based Enterprise Intrusion Detection Infrastructure roesch@sourcefire.com - http://www.sourcefire.com Snort: Open Source Network IDS - http://www.snort.org - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (Darwin) iD8DBQE+Y+Rtqj0FAQQ3KOARAurPAJ9qzBQCzOG2xxcn2IBfuOlDMjPhJwCfdgiX M+f1Ccdy03evjCtBT1rq6YQ= =RhwD - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. 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 may 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 author's website 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/render.html?cid=1980 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 member emergencies only. -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBPmTEjyh9+71yA2DNAQEOQAQAk8lWKTddLOyJI6fiHET+ZmHOpjfRVJGQ EGp4piyAZKGINVLjcNJ1muKiAorp6ZCHiJ91T02plLdcAkLjYyFdi6ZBWozggsxo AQ64981V91ceF+ftx7Ec0/0L+Q7AIyNa/6n4tJDroEF+SrWqWqzUn4Lgq6jBLKVv Jcn0W2HP9YY= =DIsb -----END PGP SIGNATURE-----