USN-82-1: Linux kernel vulnerabilities

Releases

• Ubuntu 4.10

Details

CAN-2004-0176:

Michael Kerrisk noticed an insufficient permission checking in the
shmctl() function. Any process was permitted to lock/unlock any
System V shared memory segment that fell within the the
RLIMIT_MEMLOCK limit (that is the maximum size of shared memory that
unprivileged users can acquire). This allowed am unprivileged user
process to unlock locked memory of other processes, thereby allowing
them to be swapped out. Usually locked shared memory is used to
store passphrases and other sensitive content which must not be
written to the swap space (where it could be read out even after a
reboot).

CAN-2005-0177:

OGAWA Hirofumi noticed that the table sizes in nls_ascii.c were
incorrectly set to 128 instead of 256. This caused a buffer overflow
in some cases which could be exploited to crash the kernel.

CAN-2005-0178:

A race condition was found in the terminal handling of the
“setsid()” function, which is used to start new process sessions.

http://oss.sgi.com/archives/netdev/2005-01/msg01036.html:

David Coulson noticed a design flaw in the netfilter/iptables module.
By sending specially crafted packets, a remote attacker could exploit
this to crash the kernel or to bypass firewall rules.

Fixing this vulnerability required a change in the Application
Binary Interface (ABI) of the kernel. This means that third party
user installed modules might not work any more with the new kernel,
so this fixed kernel has a new ABI version number. You have to
recompile and reinstall all third party modules.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 4.10

• linux-image-2.6.8.1-5-amd64-k8-smp -
• linux-image-2.6.8.1-5-686 -
• linux-image-2.6.8.1-5-amd64-generic -
• linux-image-2.6.8.1-5-powerpc-smp -
• linux-image-2.6.8.1-5-k7-smp -
• linux-image-2.6.8.1-5-power4-smp -
• linux-image-2.6.8.1-5-power3-smp -
• linux-image-2.6.8.1-5-amd64-xeon -
• linux-image-2.6.8.1-5-k7 -
• linux-image-2.6.8.1-5-power3 -
• linux-image-2.6.8.1-5-power4 -
• linux-image-2.6.8.1-5-686-smp -
• linux-image-2.6.8.1-5-powerpc -
• linux-image-2.6.8.1-5-amd64-k8 -
• linux-source-2.6.8.1 -
• linux-image-2.6.8.1-5-386 -

In general, a standard system update will make all the necessary changes.

References

• CVE-2005-0178
• CVE-2005-0176
• CVE-2005-0177
• http://oss.sgi.com/archives/netdev/2005-01/msg01036.html