7540094 2001-11-20 14:15 -0500 /221 rader/ CERT Advisory <cert-advisory@cert.org> Sänt av: owner-root@lysator.liu.se Importerad: 2001-11-20 22:47 av Brevbäraren Extern mottagare: cert-advisory@cert.org Mottagare: Bellman -- The Recursive Hacker <14586> Mottaget: 2001-11-20 22:50 Mottagare: Bugtraq (import) <19826> Sänt: 2001-11-21 02:42 Ärende: CERT Summary CS-2001-04 ------------------------------------------------------------ From: CERT Advisory <cert-advisory@cert.org> To: cert-advisory@cert.org Message-ID: <CS-2001-04.1@cert.org> -----BEGIN PGP SIGNED MESSAGE----- CERT Summary CS-2001-04 November 20, 2001 Each quarter, the CERT Coordination Center (CERT/CC) issues the CERT Summary to draw attention to the types of attacks reported to our incident response team, as well as other noteworthy incident and vulnerability information. The summary includes pointers to sources of information for dealing with the problems. Past CERT summaries are available from: CERT Summaries http://www.cert.org/summaries/ ______________________________________________________________________ Recent Activity Since the last regularly scheduled CERT summary, issued in August 2001 (CS-2001-03), we have seen a new worm known as "Nimda," as well as active exploitation of a vulnerability in Microsft DNS servers. In addition, we have published a paper on denial of service trends, issued a new PGP key, and updated the UNIX Security Checklist. For more current information on activity being reported to the CERT/CC, please visit the CERT/CC Current Activity page. The Current Activity page is a regularly updated summary of the most frequent, high-impact types of security incidents and vulnerabilities being reported to the CERT/CC. The information on the Current Activity page is reviewed and updated as reporting trends change. CERT/CC Current Activity http://www.cert.org/current/current_activity.html 1. W32/Nimda Worm Over the past several months, we have received reports of malicious code known as the "W32/Nimda Worm." This worm can propogate itself via several methods, including email, network shares, or by visiting an infected web site. On September 18, the CERT/CC issued an advisory on Nimda. CERT Advisory CA-2001-26: Nimda Worm http://www.cert.org/advisories/CA-2001-26.html 2. Exploitation of Vulnerability in SSH1 CRC-32 Compensation Attack Detector The CERT/CC has received multiple reports of systems being compromised via the CRC-32 compensation attack detector vulnerability (VU#945216). On November 5, the CERT/CC released an incident note which describes system compromises via a vulnerability in the SSH1 (Secure Shell Protocol v1) CRC-32 attack detection code. Consequentially, we are also receiving reports of increased scanning activity for the SSH service (22/tcp). Incident Note IN 2001-12: Exploitation of vulnerability in SSH1 CRC-32 compensation attack detector http://www.cert.org/incident_notes/IN-2001-12.html Vulnerability Note #945216: SSH CRC32 attack detection code contains remote integer overflow http://www.kb.cert.org/vuls/id/945216 3. DNS Cache Poisoning in Microsoft DNS Servers The CERT/CC has received reports from sites experiencing cache corruption on systems running Microsoft DNS Server. We issued an incident note which describes this corruption and its impact on systems. The default configuration of this software allows data from malicious or incorrectly configured DNS servers to be cached by a Microsoft DNS server. This corruption can result in erroneous DNS information being returned to clients which use this server. Incident Note IN-2001-11: Cache Corruption on Microsoft DNS Servers http://www.cert.org/incident_notes/IN-2001-11.html Vulnerability Note #109475: Microsoft Windows NT and 2000 Domain Name Servers allow non-authoritative RRs to be cached by default http://www.kb.cert.org/vuls/id/109475 4. Trends In Denial Of Service Attack Technology This paper describes the current and possible future states of denial of service (DoS) technology. This document is in Adobe Acrobat format, and requires Acrobat Reader. Trends In Denial Of Service Attack Technology http://www.cert.org/archive/pdf/DoS_trends.pdf ______________________________________________________________________ UNIX Security Checklist Version 2.0 The CERT Coordination Center and the Australian Computer Emergency Response Team (AusCERT) have jointly published version 2.0 of the UNIX Security Checklist which details steps to improve the security of UNIX Operating Systems. We encourage system administrators to review all sections of this document and, if appropriate, modify their systems accordingly to fix potential weaknesses. AUSCERT UNIX Security Checklist http://www.cert.org/tech_tips/AUSCERT_checklist2.0.html ______________________________________________________________________ New CERT/CC PGP Key On October 1, the CERT/CC issued a new PGP key, which should be used when sending sensitive information to the CERT/CC. CERT/CC PGP Public Key https://www.cert.org/pgp/cert_pgp_key.asc Sending Sensitive Information To The CERT/CC http://www.cert.org/contact_cert/encryptmail.html ______________________________________________________________________ What's New and Updated Since the last CERT Summary, we have published new and updated * Advisories http://www.cert.org/advisories/ * Congressional Testimony http://www.cert.org/congressional_testimony/ * Incident Notes http://www.cert.org/incident_notes/ * CERT/CC Statistics http://www.cert.org/stats/cert_stats.html * Tech Tips http://www.cert.org/tech_tips/ * Training Schedule http:/www.cert.org/training/ * UNIX Security Checklist v2.0 http://www.cert.org/tech_tips/unix_security_checklist2.0.html ______________________________________________________________________ This document is available from: http://www.cert.org/summaries/CS-2001-04.html ______________________________________________________________________ CERT/CC Contact Information Email: cert@cert.org Phone: +1 412-268-7090 (24-hour hotline) Fax: +1 412-268-6989 Postal address: CERT Coordination Center Software Engineering Institute Carnegie Mellon University Pittsburgh PA 15213-3890 U.S.A. CERT/CC personnel answer the hotline 08:00-17:00 EST(GMT-5) / EDT(GMT-4) Monday through Friday; they are on call for emergencies during other hours, on U.S. holidays, and on weekends. Using encryption We strongly urge you to encrypt sensitive information sent by email. Our public PGP key is available from http://www.cert.org/CERT_PGP.key If you prefer to use DES, please call the CERT hotline for more information. Getting security information CERT publications and other security information are available from our web site http://www.cert.org/ To subscribe to the CERT mailing list for advisories and bulletins, send email to majordomo@cert.org. Please include in the body of your message subscribe cert-advisory * "CERT" and "CERT Coordination Center" are registered in the U.S. Patent and Trademark Office. ______________________________________________________________________ NO WARRANTY Any material furnished by Carnegie Mellon University and the Software Engineering Institute is furnished on an "as is" basis. Carnegie Mellon University makes no warranties of any kind, either expressed or implied as to any matter including, but not limited to, warranty of fitness for a particular purpose or merchantability, exclusivity or results obtained from use of the material. Carnegie Mellon University does not make any warranty of any kind with respect to freedom from patent, trademark, or copyright infringement. _________________________________________________________________ Conditions for use, disclaimers, and sponsorship information Copyright ©2001 Carnegie Mellon University. -----BEGIN PGP SIGNATURE----- Version: PGP 6.5.8 iQCVAwUBO/qnUKCVPMXQI2HJAQFqJwP9Fdg7Z6LrdCAGgshO9zPojFjt/yV95bk8 dzt+RfWC/4sSuFipx1Db6c3UvBUwIMqW+JaryT21haHLWRatkgWGw/89hTsBfY5J iEgPc+sRagEJ/w6gOas5N2B+4uNApXU9Fj0S0IgfaLulIfixtkfJkKUAHVjFxqAk MRViE3BdE9A= =OX1Z -----END PGP SIGNATURE----- (7540094) /CERT Advisory <cert-advisory@cert.org>/(Ombruten)