5.7 - RHSA-2011:1532

Problem Description:

An updated kexec-tools package that fixes three security issues, various bugs, and adds enhancements is now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64

3. Description:

Kexec allows for booting a Linux kernel from the context of an already running kernel.

Kdump used the SSH (Secure Shell) "StrictHostKeyChecking=no" option when dumping to SSH targets, causing the target kdump server's SSH host key not to be checked. This could make it easier for a man-in-the-middle attacker on the local network to impersonate the kdump SSH target server and possibly gain access to sensitive information in the vmcore dumps. (CVE-2011-3588)

mkdumprd created initrd files with world-readable permissions. A local user could possibly use this flaw to gain access to sensitive information, such as the private SSH key used to authenticate to a remote server when kdump was configured to dump to an SSH target. (CVE-2011-3589)

mkdumprd included unneeded sensitive files (such as all files from the "/root/.ssh/" directory and the host's private SSH keys) in the resulting initrd. This could lead to an information leak when initrd files were previously created with world-readable permissions. Note: With this update, only the SSH client configuration, known hosts files, and the SSH key configured via the newly introduced sshkey option in "/etc/kdump.conf" are included in the initrd. The default is the key generated when running the "service kdump propagate" command, "/root/.ssh/kdump_id_rsa". (CVE-2011-3590)

Red Hat would like to thank Kevan Carstensen for reporting these issues.

This update also fixes several bugs and adds various enhancements. Space precludes documenting all of these changes in this advisory. Documentation for these bug fixes and enhancements will be available shortly from the Technical Notes document, linked to in the References section.

All kexec-tools users should upgrade to this updated package, which contains backported patches to resolve these issues and add these enhancements.

4. Solution:

Before applying this update, make sure all previously-released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/kb/docs/DOC-11259

5. Bugs fixed (http://bugzilla.redhat.com/):

681796 - Pass "noefi acpi_rsdp=X" to the second kernel 708503 - fails to build without downstream patches 716439 - CVE-2011-3588 CVE-2011-3589 CVE-2011-3590 kexec-tools: Multiple security flaws by management of kdump core files and ramdisk images 719105 - mkdumprd hang in depsolve_modlist when running kernel is not target kernel 725484 - kexec-tools: x86: Start using nr_cpus=1 instead of maxcpus=1 727892 - kexec-tools: Warn a user to use maxcpus=1 instead of nr_cpus=1 for older kernels 731394 - [kexec-tools] Remove warning when kdump service starts 734528 - kexec-tools: Add memory usage debugging capability in second kernel 739050 - non-fatal <unknown> scriptlet failure in rpm package fence-agents