ID

VAR-200208-0244

CVE

CVE-2002-0656

TITLE

OpenSSL clients contain a buffer overflow during the SSL3 handshake process

DESCRIPTION

Buffer overflows in OpenSSL 0.9.6d and earlier, and 0.9.7-beta2 and earlier, allow remote attackers to execute arbitrary code via (1) a large client master key in SSL2 or (2) a large session ID in SSL3. The DNS stub resolver library in ISC BIND 4.9.2 through 4.9.10 contains buffer overflows in code that handles responses for network name and address requests. Other resolver libraries derived from BIND 4 such as BSD libc, GNU glibc, and those used by System V UNIX systems may also be affected. An attacker could execute arbitrary code with the privileges of the application that made the request or cause a denial of service. This vulnerability is resolved in BIND versions 4.9.11, 8.2.7, 8.3.4, and BIND 9. Based on recent reports, we believe this vulnerability is being actively exploited. OpenSSL is an open-source implementation of the Secure Sockets Layer (SSL) protocol. A remotely exploitable vulnerability exists in OpenSSL servers that could lead to the execution of arbitrary code on the server. OpenSSL Is OpenSSL On the server SSL version 2.0 ( Less than, SSLv2) The buffer overflow vulnerability is caused by handshake processing. The issue occurs in the handling of the client key value during the negotiation of the SSLv2 protocol. ***UPDATE: A worm that likely exploits this vulnerability has been discovered propagating in the wild. Additionally, this code includes peer-to-peer and distributed denial-of-service capabilities. There have been numerous reports of intrusions in Europe. It is not yet confirmed whether this vulnerability is in OpenSSL, mod_ssl, or another component. Administrators are advised to upgrade to the most recent versions or to disable Apache, if possible, until more information is available. OpenSSL is prone to a buffer-overflow vulnerability involving overly long SSLv3 session IDs. It supports a variety of encryption algorithms, including symmetric ciphers, hash algorithms, security hashing algorithm, etc. -----BEGIN PGP SIGNED MESSAGE----- CERT Summary CS-2002-04 November 26, 2002 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 2002 (CS-2002-03), we have seen trojan horses for three popular distributions, new self-propagating malicious code (Apache/mod_ssl), and multiple vulnerabilities in BIND. In addition, we have issued a new PGP Key. 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. Reports received by the CERT/CC indicate that the Apache/mod_ssl worm has already infected thousands of systems. Over a month earlier, the CERT/CC issued an advisory (CA-2002-23) describing four remotely exploitable buffer overflows in OpenSSL. Trojan Horse Sendmail Distribution The CERT/CC has received confirmation that some copies of the source code for the Sendmail package have been modified by an intruder to contain a Trojan horse. These copies began to appear in downloads from the FTP server ftp.sendmail.org on or around September 28, 2002. On October 8, 2002, the CERT/CC issued an advisory (CA-2002-28) describing various methods to verify software authenticity. CERT Advisory CA-2002-28 Trojan Horse Sendmail Distribution http://www.cert.org/advisories/CA-2002-28.html 3. Trojan Horse tcpdump and libpcap Distributions The CERT/CC has received reports that some copies of the source code for libpcap, a packet acquisition library, and tcpdump, a network sniffer, have been modified by an intruder and contain a Trojan horse. These modified distributions began to appear in downloads from the HTTP server www.tcpdump.org on or around Nov 11, 2002. The CERT/CC issued an advisory (CA-2002-30) listing MD5 checksums and official distribution sites for libpcap and tcpdump. CERT Advisory CA-2002-30 Trojan Horse tcpdump and libpcap Distributions http://www.cert.org/advisories/CA-2002-30.html 4. Multiple Vulnerabilities in BIND The CERT/CC has documented multiple vulnerabilities in BIND, the popular domain name server and client library software package from the Internet Software Consortium (ISC). Several vulnerabilities are referenced in the advisory; they are listed here individually. CERT Advisory CA-2002-31 Multiple Vulnerabilities in BIND http://www.cert.org/advisories/CA-2002-31.html Vulnerability Note #852283 Cached malformed SIG record buffer overflow http://www.kb.cert.org/vuls/id/852283 Vulnerability Note #229595 Overly large OPT record assertion http://www.kb.cert.org/vuls/id/229595 Vulnerability Note #581682 ISC Bind 8 fails to properly dereference cache SIG RR elements invalid expiry times from the internal database http://www.kb.cert.org/vuls/id/581682 Vulnerability Note #844360 Domain Name System (DNS) stub resolver libraries vulnerable to buffer overflows via network name or address lookups http://www.kb.cert.org/vuls/id/844360 5. Heap Overflow Vulnerability in Microsoft Data Access Components (MDAC) On November 21, 2002 the CERT/CC issued an advisory (CA-2002-33) describing a vulnerability in MDAC, a collection of Microsoft utilities and routines that process requests between databases and network applications. CERT Advisory CA-2002-33 Heap Overflow Vulnerability in Microsoft Data Access Components (MDAC) http://www.cert.org/advisories/CA-2002-33.html ______________________________________________________________________ New CERT/CC PGP Key On September 19, 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/ * CERT/CC Statistics http://www.cert.org/stats/cert_stats.html * Home User Security http://www.cert.org/homeusers/HomeComputerSecurity * Tech Tips http://www.cert.org/tech_tips/ * Training Schedule http:/www.cert.org/training/ ______________________________________________________________________ This document is available from: http://www.cert.org/summaries/CS-2002-04.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 \xa92002 Carnegie Mellon University. -----BEGIN PGP SIGNATURE----- Version: PGP 6.5.8 iQCVAwUBPePMQWjtSoHZUTs5AQGdxwP9HK4mSF15bMQ9MZ4mMFcLIhvdXykANg8A 6nEIAyB8CJpbuWdP7sPh3qAwaZ9BhRFEGeLakONOpoo7bmjkwAWrJHxF3b1CrgHS ZuKQsgEhnm9wpPdU6w6SG1cJBkwz70b8d7YK0vcVuKhmaW0JOx9OLGKsAe3SFePD OiZbNHX+eb8= =Mnbn -----END PGP SIGNATURE----- . OpenSSL Security Advisory [30 July 2002] This advisory consists of two independent advisories, merged, and is an official OpenSSL advisory. Advisory 1 ========== A.L. Digital Ltd and The Bunker (http://www.thebunker.net/) are conducting a security review of OpenSSL, under the DARPA program CHATS. 1. The client master key in SSL2 could be oversized and overrun a buffer. Exploit code is NOT available at this time. 2. 3. This issues only affects OpenSSL 0.9.7 before 0.9.7-beta3 with Kerberos enabled. 4. Various buffers for ASCII representations of integers were too small on 64 bit platforms. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2002-0656 to issues 1-2, CAN-2002-0657 to issue 3, and CAN-2002-0655 to issue 4. In addition various potential buffer overflows not known to be exploitable have had assertions added to defend against them. Who is affected? ---------------- Everyone using OpenSSL 0.9.6d or earlier, or 0.9.7-beta2 or earlier or current development snapshots of 0.9.7 to provide SSL or TLS is vulnerable, whether client or server. 0.9.6d servers on 32-bit systems with SSL 2.0 disabled are not vulnerable. SSLeay is probably also affected. Recommendations --------------- Apply the attached patch to OpenSSL 0.9.6d, or upgrade to OpenSSL 0.9.6e. Recompile all applications using OpenSSL to provide SSL or TLS. A patch for 0.9.7 is available from the OpenSSL website (https://www.openssl.org/). Servers can disable SSL2, alternatively disable all applications using SSL or TLS until the patches are applied. Users of 0.9.7 pre-release versions with Kerberos enabled will also have to disable Kerberos. Client should be disabled altogether until the patches are applied. Known Exploits -------------- There are no know exploits available for these vulnerabilities. As noted above, Neohapsis have demonstrated internally that an exploit is possible, but have not released the exploit code. References ---------- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0655 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0656 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0657 Acknowledgements ---------------- The project leading to this advisory is sponsored by the Defense Advanced Research Projects Agency (DARPA) and Air Force Research Laboratory, Air Force Materiel Command, USAF, under agreement number F30602-01-2-0537. The patch and advisory were prepared by Ben Laurie. Advisory 2 ========== Vulnerabilities --------------- The ASN1 parser can be confused by supplying it with certain invalid encodings. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2002-0659 to this issue. Who is affected? ---------------- Any OpenSSL program which uses the ASN1 library to parse untrusted data. This includes all SSL or TLS applications, those using S/MIME (PKCS#7) or certificate generation routines. Recommendations --------------- Apply the patch to OpenSSL, or upgrade to OpenSSL 0.9.6e. Recompile all applications using OpenSSL. Users of 0.9.7 pre-release versions should apply the patch or upgrade to 0.9.7-beta3 or later. Recompile all applications using OpenSSL. References ---------- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0659 Acknowledgements ---------------- This vulnerability was discovered by Adi Stav <stav@mercury.co.il> and James Yonan <jim@ntlp.com> independently. The patch is partly based on a version by Adi Stav. The patch and advisory were prepared by Dr. Stephen Henson. Combined patches for OpenSSL 0.9.6d: https://www.openssl.org/news/patch_20020730_0_9_6d.txt Combined patches for OpenSSL 0.9.7 beta 2: https://www.openssl.org/news/patch_20020730_0_9_7.txt URL for this Security Advisory: https://www.openssl.org/news/secadv_20020730.txt

AFFECTED PRODUCTS

CVSS

PROBLEMTYPE DATA

THREAT TYPE

network

TYPE

Boundary Condition Error

CONFIGURATIONS

EXPLOIT AVAILABILITY

PATCH

EXTERNAL IDS

REFERENCES

CREDITS

A.L. Digital Ltd The Bunker

SOURCES

LAST UPDATE DATE

2024-11-22T22:13:13.069000+00:00

SOURCES UPDATE DATE

SOURCES RELEASE DATE