Check Point VPN-1 ASN.1 Decoding Remote Compromise
Internet Security Systems Protection Advisory July 28, 2004 Check Point VPN-1 ASN.1 Decoding Remote Compromise Summary: ISS has shipped protection for a flaw X-Force has discovered in CheckPoint VPN-1 Server. The Check Point VPN-1 product is widely relied upon to provide secure remote access to private networks from less trusted network environments. When establishing an encrypted connection to a virtual private network (VPN), it is possible for an attacker to trigger a buffer overflow vulnerability in an ASN.1 decoding library within the VPN-1 product. Note: The vulnerability described in this advisory is distinct and separate from previously announced issues and customers are advised to assess their protection accordingly. ISS Protection Strategy: ISS has provided preemptive protection for these vulnerabilities. We recommend that all customers apply applicable ISS product updates. Network Sensor 7.0, Proventia A and G: XPU 22.26 / July 12, 2004 ISAKMP_ASN1_Overflow Proventia M: XPU 1.24 / July 12, 2004 ISAKMP_ASN1_Overflow Internet Scanner 7.0: XPU 7.32/ July 28, 2004 VPN1-ASN1-Decoding-BO These updates are now available from the ISS Download Center at: http://www.iss.net/download. Business Impact: Compromise of VPN-1 networks may lead to exposure of confidential information, loss of productivity, and further network compromise. Successful exploitation of this vulnerability could be used to gain unauthorized access to networks being protected by Check Point¿s VPN-1 product. No authentication would be required for an attacker to leverage this vulnerability to compromise a VPN, and operational VPN-1 installations will likely be vulnerable in their default configurations. Affected Products: VPN-1/FireWall-1 NG with Application Intelligence R54 VPN-1/FireWall-1 NG with Application Intelligence R55 VPN-1/FireWall-1 NG with Application Intelligence R55W VPN-1/FireWall-1 Next Generation FP3 VPN-1/FireWall-1 VSX FireWall-1 GX VPN-1 SecuRemote/SecureClient All Versions Note: Additional versions may be affected, please contact your vendor for confirmation. Description: Internet Key Exchange (IKE) is used to negotiate and exchange keys for encrypted transport or tunneling of network traffic over a Virtual Private Network (VPN). The network protocol used to facilitate this exchange is the Internet Security Association and Key Management Protocol (ISAKMP). Various protocol fields within ISAKMP are ASN.1 encoded, and the VPN-1 server will decode these fields as part of the initial encrypted connection setup. When performing this decoding, it is possible for an attacker to trigger an arbitrary-length heap overflow which may result in complete compromise of the VPN-1 server. This vulnerability can be triggered by an unauthenticated remote attacker through a single-packet attack. If UDP-based IKE negotiation is enabled, it may be possible for attackers to conceal the source of attacks and perform a blind-spoofed attack. The ISS X-Press Updates detailed above have the ability to protect against attack attempts targeted at VPN-1 servers. Additional Recommendations: Vendor-supplied patches for the issue described in this advisory are available from: http://www.checkpoint.com/techsupport/alerts/asn1.html Additional Information: Check Point Security Center: http://www.checkpoint.com/securitycenter/ The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2004-0699 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. Credit: This vulnerability was discovered and researched by Mark Dowd and Neel Mehta of the ISS X-Force. ______ Internet Security Systems, Inc. (ISS) is the trusted expert to global enterprises and world governments, providing products and services that protect against Internet threats. An established world leader in security since 1994, ISS delivers proven cost efficiencies and reduces regulatory and business risk across the enterprise for more than 11,000 customers worldwide. ISS products and services are based on the proactive security intelligence conducted by ISS¿ X-Force¿ research and development team ¿ the unequivocal world authority in vulnerability and threat research. Headquartered in Atlanta, Internet Security Systems has additional operations throughout the Americas, Asia, Australia, Europe and the Middle East. 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X-Force PGP Key available on MIT's PGP key server and PGP.com's key server, as well as at http://www.iss.net/security_center/sensitive.php Please send suggestions, updates, and comments to: xforce@iss.net of Internet Security Systems, Inc.