6389239 2001-04-19 16:00 -0400 /87 rader/ <bugzilla@REDHAT.COM> Sänt av: joel@lysator.liu.se Importerad: 2001-04-20 11:18 av Brevbäraren Extern mottagare: BUGTRAQ@SECURITYFOCUS.COM Externa svar till: bugzilla@REDHAT.COM Mottagare: Bugtraq (import) <16675> Ärende: [RHSA-2001:052-02] FTP iptables vulnerability in 2.4 kernel ------------------------------------------------------------ From: bugzilla@REDHAT.COM To: BUGTRAQ@SECURITYFOCUS.COM Message-ID: <200104192000.f3JK0RN12708@porkchop.redhat.com> --------------------------------------------------------------------- Red Hat, Inc. Red Hat Security Advisory Synopsis: FTP iptables vulnerability in 2.4 kernel Advisory ID: RHSA-2001:052-02 Issue date: 2001-04-19 Updated on: 2001-04-19 Product: Red Hat Linux Keywords: FTP iptables ip_conntrack_ftp Cross references: Obsoletes: --------------------------------------------------------------------- 1. Topic: A security hole has been found that does not affect the default configuration of Red Hat Linux, but can affect some custom configurations of Red Hat Linux 7.1 only. The bug is specific to the Linux 2.4 kernel series. 2. Relevant releases/architectures: 3. Problem description: A vulnerability in iptables "RELATED" connection tracking has been discovered. When using iptables to allow FTP "RELATED" connections through the firewall, carefully constructed PORT commands can open arbitrary holes in the firewall. The iptables system is included in the 2.4 kernel series, but not in the earlier 2.2 kernel series used in Red Hat Linux 6.x and Red Hat Linux 7.0. Red Hat Linux 7.1 uses a 2.4 kernel and provides the ip_conntrack_ftp module that has this bug. However, Red Hat Linux does not currently configure iptables (the default firewall configuration uses ipchains instead), so unless you have explicitly configured iptables and enabled FTP "RELATED" connections through the firewall, you are not vulnerable to attack. 4. Solution: Red Hat will be releasing a kernel with this and other bugs fixed shortly. In the meantime, we strongly recommend that users of iptables not allow FTP "RELATED" connections. 5. Bug IDs fixed (http://bugzilla.redhat.com/bugzilla for more info): 6. RPMs required: 7. Verification: MD5 sum Package Name -------------------------------------------------------------------------- These packages are GPG signed by Red Hat, Inc. for security. Our key is available at: http://www.redhat.com/corp/contact.html You can verify each package with the following command: rpm --checksig <filename> If you only wish to verify that each package has not been corrupted or tampered with, examine only the md5sum with the following command: rpm --checksig --nogpg <filename> 8. References: http://www.tempest.com.br/advisories/01-2001.html http://www.securityfocus.com/templates/archive.pike?list=1&mid=177070 http://slashdot.org/comments.pl?sid=01/04/19/047249&cid=36 Copyright(c) 2000, 2001 Red Hat, Inc. (6389239) / <bugzilla@REDHAT.COM>/------------------