--------------------------------------------------------------------- Red Hat, Inc. Red Hat Security Advisory Synopsis: Updated at package available Advisory ID: RHSA-2002:015-15 Issue date: 2002-01-15 Updated on: 2002-02-07 Product: Red Hat Linux Keywords: at security heap corruption environment Cross references: Obsoletes: --------------------------------------------------------------------- 1. Topic: This updated at package fixes two minor problems and one major problem where the environment can get wiped out prior to the execution of a scheduled command. For versions of Red Hat Linux prior to 7.2, this package also fixes a potential security vulnerability which can result in heap corruption (Red Hat Linux 7.2 is not vulnerable to this security exploit). Update 2002-02-01: The package for Red Hat Linux 6.2 tried to source a file in /etc/init.d, which doesn't exist on a standard system. 2. Relevant releases/architectures: Red Hat Linux 6.2 - alpha, i386, sparc Red Hat Linux 7.0 - alpha, i386 Red Hat Linux 7.1 - alpha, i386, ia64 Red Hat Linux 7.2 - i386, ia64 3. Problem description: A server running the latest version of at could have commands that depend on the current environment (for example, the PATH) which would then fail or run incorrectly because the environment would not be accessible when the command was executed at a later time. Additionally, in versions of Red Hat Linux prior to 7.2 a malicious local user could specify an execution time is in a carefully drafted format causing a heap corruption bug. Since the at command is installed as setuid root this bug can be exploited. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2002-0004 to this issue. Thanks to zen-parse for reporting this vulnerability. In addition to the fixed heap corruption, file handling security on all versions of at has been improved by adding the O_EXCL (exclusive) option to an open system call. 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 (http://bugzilla.redhat.com/bugzilla for more info): 49491 - all environment is wiped out prior to executing user command 51253 - Wrong pointer to time syntax in man page 52626 - "at" RPM says that /var/spool/at/.SEQ should be executable 6. RPMs required: Red Hat Linux 6.2: SRPMS: ftp://updates.redhat.com/6.2/en/os/SRPMS/at-3.1.8-22.2.src.rpm alpha: ftp://updates.redhat.com/6.2/en/os/alpha/at-3.1.8-22.2.alpha.rpm i386: ftp://updates.redhat.com/6.2/en/os/i386/at-3.1.8-22.2.i386.rpm sparc: ftp://updates.redhat.com/6.2/en/os/sparc/at-3.1.8-22.2.sparc.rpm Red Hat Linux 7.0: SRPMS: ftp://updates.redhat.com/7.0/en/os/SRPMS/at-3.1.8-23.src.rpm alpha: ftp://updates.redhat.com/7.0/en/os/alpha/at-3.1.8-23.alpha.rpm i386: ftp://updates.redhat.com/7.0/en/os/i386/at-3.1.8-23.i386.rpm Red Hat Linux 7.1: SRPMS: ftp://updates.redhat.com/7.1/en/os/SRPMS/at-3.1.8-23.src.rpm alpha: ftp://updates.redhat.com/7.1/en/os/alpha/at-3.1.8-23.alpha.rpm i386: ftp://updates.redhat.com/7.1/en/os/i386/at-3.1.8-23.i386.rpm ia64: ftp://updates.redhat.com/7.1/en/os/ia64/at-3.1.8-23.ia64.rpm Red Hat Linux 7.2: SRPMS: ftp://updates.redhat.com/7.2/en/os/SRPMS/at-3.1.8-23.src.rpm i386: ftp://updates.redhat.com/7.2/en/os/i386/at-3.1.8-23.i386.rpm ia64: ftp://updates.redhat.com/7.2/en/os/ia64/at-3.1.8-23.ia64.rpm 7. Verification: MD5 sum Package Name -------------------------------------------------------------------------- beab8c80838d3920d758a2e8e5b5e3b2 6.2/en/os/SRPMS/at-3.1.8-22.2.src.rpm 31a1aac9c620778fe24a5d9c73b468c6 6.2/en/os/alpha/at-3.1.8-22.2.alpha.rpm a5ea88124398a0b937dd93e93d62c3bd 6.2/en/os/i386/at-3.1.8-22.2.i386.rpm 3ee8b5c53f23d0eae9bd78c69621ff78 6.2/en/os/sparc/at-3.1.8-22.2.sparc.rpm b1f62f4b41e12a54a1f73d639363a638 7.0/en/os/SRPMS/at-3.1.8-23.src.rpm 97e27a1d2dc0f08d8f118209a891689a 7.0/en/os/alpha/at-3.1.8-23.alpha.rpm ea793fd803f10c8fa66abb8191fefb9b 7.0/en/os/i386/at-3.1.8-23.i386.rpm b1f62f4b41e12a54a1f73d639363a638 7.1/en/os/SRPMS/at-3.1.8-23.src.rpm 97e27a1d2dc0f08d8f118209a891689a 7.1/en/os/alpha/at-3.1.8-23.alpha.rpm ea793fd803f10c8fa66abb8191fefb9b 7.1/en/os/i386/at-3.1.8-23.i386.rpm 8fed88d53824e98f509289c42ea01237 7.1/en/os/ia64/at-3.1.8-23.ia64.rpm b1f62f4b41e12a54a1f73d639363a638 7.2/en/os/SRPMS/at-3.1.8-23.src.rpm ea793fd803f10c8fa66abb8191fefb9b 7.2/en/os/i386/at-3.1.8-23.i386.rpm 8fed88d53824e98f509289c42ea01237 7.2/en/os/ia64/at-3.1.8-23.ia64.rpm These packages are GPG signed by Red Hat, Inc. for security. Our key is available at: http://www.redhat.com/about/contact/pgpkey.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://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0004 Copyright(c) 2000, 2001 Red Hat, Inc.