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Red Hat 7.1-8.0 RHSA-2003:221-01 Critical Signal Issue Fix

Updated stunnel packages are now available for Red Hat Linux 7.1, 7.2, 7.3,and 8.0. These updates correct a potential vulnerability in stunnel'ssignal handling.. ` --------------------------------------------------------------------- Red Hat Security Advisory Synopsis: Updated stunnel packages fix signal vulnerability Advisory ID: RHSA-2003:221-01 Issue date: 2003-07-25 Updated on: 2003-07-25 Product: Red Hat Linux Keywords: stunnel signal handler reentrancy DoS Cross references: Obsoletes: RHSA-2002:002 CVE Names: CAN-2002-1563 --------------------------------------------------------------------- 1. Topic: Updated stunnel packages are now available for Red Hat Linux 7.1, 7.2, 7.3, and 8.0. These updates correct a potential vulnerability in stunnel's signal handling. 2. Relevant releases/architectures: Red Hat Linux 7.1 - i386 Red Hat Linux 7.2 - i386, ia64 Red Hat Linux 7.3 - i386 Red Hat Linux 8.0 - i386 3. Problem description: Stunnel is a wrapper for network connections. It can be used to tunnel an unencrypted network connection over a secure connection (encrypted using SSL or TLS) or to provide a secure means of connecting to services that do not natively support encryption. When configured to listen for incoming connections (instead of being invoked by xinetd), stunnel can be configured to either start a thread or a child process to handle each new connection. If Stunnel is configured to start a new child process to handle each connection, it will receive a SIGCHLD signal when that child exits. Stunnel versions prior to 4.04 would perform tasks in the SIGCHLD signal handler which, if interrupted by another SIGCHLD signal, could be unsafe. This could lead to a denial of service. All users are urged to upgrade to these errata packages, which modify stunnel's signal handler so that it is not vulnerable to this issue. NOTE: After upgrading, any instances of stunnel configured to run in daemon mode should berestarted, and any active network connections that are currently being serviced by stunnel should be terminated and reestablished. 4. Solution: Before applying this update, make sure all previously released errata relevant to your system have been applied. To update all RPMs for your particular architecture, run: rpm -Fvh [filenames] where [filenames] is a list of the RPMs you wish to upgrade. Only those RPMs which are currently installed will be updated. Those RPMs which are not installed but included in the list will not be updated. Note that you can also use wildcards (*.rpm) if your current directory *only* contains the desired RPMs. Please note that this update is also available via Red Hat Network. Many people find this an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. 5. Bug IDs fixed ( for more info): 82325 - stunnel security errata required 6. RPMs required: Red Hat Linux 7.1: SRPMS: i386: Red Hat Linux 7.2: SRPMS: i386: ia64: Red Hat Linux 7.3: SRPMS: i386: Red Hat Linux 8.0: SRPMS: i386: 7. Verification: MD5 sum Package Name -------------------------------------------------------------------------- e20a6bcf06735897d4b9f7a05b9ded3f 7.1/en/os/SRPMS/stunnel-3.22-5.7.1.src.rpm 38a38be900e55173493db34a1d0fdddd 7.1/en/os/i386/stunnel-3.22-5.7.1.i386.rpm d74e461c13ccb49a48bac85560b40287 7.2/en/os/SRPMS/stunnel-3.22-5.7.3.src.rpm bc60108d725ce1b88bfdc16db0b9ee6f 7.2/en/os/i386/stunnel-3.22-5.7.3.i386.rpm f017a9e4373a8478342961e430c8405f 7.2/en/os/ia64/stunnel-3.22-5.7.3.ia64.rpm d74e461c13ccb49a48bac85560b40287 7.3/en/os/SRPMS/stunnel-3.22-5.7.3.src.rpm bc60108d725ce1b88bfdc16db0b9ee6f 7.3/en/os/i386/stunnel-3.22-5.7.3.i386.rpm 37e3c19c87b1c47a3a503823ce19a687 8.0/en/os/SRPMS/stunnel-3.22-5.8.0.src.rpm 10a5bac0cf90d31b6db4b49abc74ca4b8.0/en/os/i386/stunnel-3.22-5.8.0.i386.rpm These packages are GPG signed by Red Hat for security. Our key is available from Product Signing Keys - Red Hat Customer Portal You can verify each package with the following command: rpm --checksig -v If you only wish to verify that each package has not been corrupted or tampered with, examine only the md5sum with the following command: md5sum 8. References: http://marc.theaimsgroup.com/?l=stunnel-users&m=103600188215117 CVE -CVE-2002-1563 9. Contact: The Red Hat security contact is . More contact details at All Red Hat products Copyright 2003 Red Hat, Inc. `. Critical stunnel package updates for Red Hat Linux fix a serious signal handling flaw that could lead to DoS attacks.. Red Hat Updates, Stunnel Security Fix, Critical Vulnerability, Signal Handling Issue. . Severity: Critical. LinuxSecurity.com Team

Jul 25, 2003 •Critical Red Hat