Updated 2.4 kernel fixes vulnerabilities

Updated kernel packages are now available fixing several security
vulnerabilities.

[Updated 28 August 2003]
Added CAN-2003-0699 and CAN-2003-0700 to the list of security issues that
are fixed by this advisory (there are no changes to the packages themselves).

The Linux kernel handles the basic functions of the operating system.

Several security issues have been discovered affecting the Linux kernel:

CAN-2003-0461: /proc/tty/driver/serial reveals the exact character counts
for serial links. This could be used by a local attacker to infer password
lengths and inter-keystroke timings during password entry.

CAN-2003-0462: Paul Starzetz discovered a file read race condition existing
in the execve() system call, which could cause a local crash.

CAN-2003-0464: A recent change in the RPC code set the reuse flag on
newly-created sockets. Olaf Kirch noticed that his could allow normal
users to bind to UDP ports used for services such as nfsd.

CAN-2003-0476: The execve system call in Linux 2.4.x records the file
descriptor of the executable process in the file table of the calling
process, allowing local users to gain read access to restricted file
descriptors.

CAN-2003-0501: The /proc filesystem in Linux allows local users to obtain
sensitive information by opening various entries in /proc/self before
executing a setuid program. This causes the program to fail to change the
ownership and permissions of already opened entries.

CAN-2003-0550: The STP protocol is known to have no security, which could
allow attackers to alter the bridge topology. STP is now turned off by
default.

CAN-2003-0551: STP input processing was lax in its length checking, which
could lead to a denial of service.

CAN-2003-0552: Jerry Kreuscher discovered that the Forwarding table could
be spoofed by sending forged packets with bogus source addresses the same
as the local host.

CAN-2003-0699: The C-Media PCI sound driver in kernel versions prior to
2.4.21 does not use the get_user function to access userspace, which
crosses security boundaries and may facilitate the exploitation of
vulnerabilities.

CAN-2003-0700: The C-Media PCI sound driver in kernel versions prior to
2.4.22 accesses userspace without using the get_user function, which is a
potential security hole (NOTE: this issue is distinct from that described
in CAN-2003-0699).

All users are advised to upgrade to these errata packages, which contain
backported security patches correcting these vulnerabilities.


Important:

If you use Red Hat Linux 7.1, you must have installed quota-3.06-9.71 from
RHSA-2003-187, and if you use Red Hat Linux 7.2 or 7.3, you must have
installed quota-3.06-9.7 from RHSA-2003-187.

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

To use Red Hat Network to upgrade the kernel, 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. Note that you need to select the
kernel explicitly if you are using the default configuration of up2date.

To install kernel packages manually, use "rpm -ivh <package>" and
modify system settings to boot the kernel you have installed. To
do this, edit /boot/grub/grub.conf and change the default entry to
"default=0" (or, if you have chosen to use LILO as your boot loader,
edit /etc/lilo.conf and run lilo)

Do not use "rpm -Uvh" as that will remove your running kernel binaries
from your system. You may use "rpm -e" to remove old kernels after
determining that the new kernel functions properly on your system.

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0461
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0462
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0464
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0476
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0501
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0550
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0551
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0552
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0699
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0700