linux-kernel-2.4.18 - several vulnerabilities

A number of vulnerabilities have been discovered in the Linux kernel.

• 
  CAN-2003-0461: /proc/tty/driver/serial in Linux 2.4.x reveals the
  exact number of characters used in serial links, which could allow
  local users to obtain potentially sensitive information such as the
  length of passwords. This bug has been fixed by restricting access
  to /proc/tty/driver/serial.
• 
  CAN-2003-0462: A race condition in the way env_start and env_end
  pointers are initialized in the execve system call and used in
  fs/proc/base.c on Linux 2.4 allows local users to cause a denial of
  service (crash).
• 
  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, which allows 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, which causes the
  program to fail to change the ownership and permissions of those
  entries.
• 
  CAN-2003-0550: The STP protocol, as enabled in Linux 2.4.x, does not
  provide sufficient security by design, which allows attackers to
  modify the bridge topology. This bug has been fixed by disabling
  STP by default.
• 
  CAN-2003-0551: The STP protocol, as enabled in Linux 2.4.x, does not
  provide sufficient security by design, which allows attackers to
  modify the bridge topology.
• 
  CAN-2003-0552: Linux 2.4.x allows remote attackers to spoof the
  bridge forwarding table via forged packets whose source addresses
  are the same as the target.
• 
  CAN-2003-0018: Linux kernel 2.4.10 through 2.4.21-pre4 does not
  properly handle the O_DIRECT feature, which allows local attackers
  with write privileges to read portions of previously deleted files,
  or cause file system corruption. This bug has been fixed by
  disabling O_DIRECT.
• 
  CAN-2003-0619: Integer signedness error in the decode_fh function of
  nfs3xdr.c in Linux kernel before 2.4.21 allows remote attackers to
  cause a denial of service (kernel panic) via a negative size value
  within XDR data of an NFSv3 procedure call.

This advisory covers only the i386 and alpha architectures. Other
architectures will be covered by separate advisories.

For the stable distribution (woody) on the i386 architecture, these
problems have been fixed in kernel-source-2.4.18 version 2.4.18-13,
kernel-image-2.4.18-1-i386 version 2.4.18-11, and
kernel-image-2.4.18-i386bf version 2.4.18-5woody4.

For the stable distribution (woody) on the alpha architecture, these
problems have been fixed in kernel-source-2.4.18 version 2.4.18-13 and
kernel-image-2.4.18-1-alpha version 2.4.18-10.

For the unstable distribution (sid) these problems are fixed in
kernel-source-2.4.20 version 2.4.20-9.

We recommend that you update your kernel packages.

If you are using the kernel installed by the installation system when
the “bf24” option is selected (for a 2.4.x kernel), you should install
the kernel-image-2.4.18-bf2.4 package. If you installed a different
kernel-image package after installation, you should install the
corresponding 2.4.18-1 kernel. You may use the table below as a
guide.

   | If "uname -r" shows: | Install this package:
   | 2.4.18-bf2.4         | kernel-image-2.4.18-bf2.4
   | 2.4.18-386           | kernel-image-2.4.18-1-386
   | 2.4.18-586tsc        | kernel-image-2.4.18-1-586tsc
   | 2.4.18-686           | kernel-image-2.4.18-1-686
   | 2.4.18-686-smp       | kernel-image-2.4.18-1-686-smp
   | 2.4.18-k6            | kernel-image-2.4.18-1-k6
   | 2.4.18-k7            | kernel-image-2.4.18-1-k7

NOTE: This kernel is binary compatible with the previous kernel
security update, but not binary compatible with the corresponding
kernel included in Debian 3.0r1. If you have not already applied the
previous security update (kernel-image-2.4.18-bf2.4 version
2.4.18-5woody1 or any of the 2.4.18-1-* kernels), then any custom
modules will need to be rebuilt in order to work with the new kernel.
New PCMCIA modules are provided for all of the above kernels.

NOTE: A system reboot will be required immediately after the upgrade
in order to replace the running kernel. Remember to read carefully
and follow the instructions given during the kernel upgrade process.