Ubuntu Security Notice USN-395-1

13th December, 2006

linux-source-2.6.12/-2.6.15/-2.6.17 vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

• Ubuntu 6.10
• Ubuntu 6.06 LTS
• Ubuntu 5.10

Details

Mark Dowd discovered that the netfilter iptables module did not
correcly handle fragmented packets. By sending specially crafted
packets, a remote attacker could exploit this to bypass firewall
rules. This has only be fixed for Ubuntu 6.10; the corresponding fix
for Ubuntu 5.10 and 6.06 will follow soon. (CVE-2006-4572)

Dmitriy Monakhov discovered an information leak in the
__block_prepare_write() function. During error recovery, this function
did not properly clear memory buffers which could allow local users to
read portions of unlinked files. This only affects Ubuntu 5.10.
(CVE-2006-4813)

ADLab Venustech Info Ltd discovered that the ATM network driver
referenced an already released pointer in some circumstances. By
sending specially crafted packets to a host over ATM, a remote
attacker could exploit this to crash that host. This does not affect
Ubuntu 6.10. (CVE-2006-4997)

Matthias Andree discovered that the NFS locking management daemon
(lockd) did not correctly handle mixing of 'lock' and 'nolock' option
mounts on the same client. A remote attacker could exploit this to
crash lockd and thus rendering the NFS imports inaccessible. This only
affects Ubuntu 5.10. (CVE-2006-5158)

The task switching code did not save and restore EFLAGS of processes.
By starting a specially crafted executable, a local attacker could
exploit this to eventually crash many other running processes. This
does not affect Ubuntu 6.10. (CVE-2006-5173)

James Morris discovered that the ip6fl_get_n() function incorrectly
handled flow labels. A local attacker could exploit this to crash the
kernel. (CVE-2006-5619)

Fabio Massimo Di Nitto discovered that the sys_get_robust_list and
sys_set_robust_list system calls lacked proper lock handling on the
powerpc platform. A local attacker could exploit this to create
unkillable processes, drain all available CPU/memory, and render the
machine unrebootable. This only affects Ubuntu 6.10. (CVE-2006-5648)

Fabio Massimo Di Nitto discovered a flaw in the alignment check
exception handling on the powerpc platform. A local attacker could
exploit this to cause a kernel panic and crash the machine.
(CVE-2006-5649)

Certain corrupted squashfs file system images caused a memory
allocation to be freed twice. By mounting a specially crafted squashfs
file system, a local attacker could exploit this to crash the kernel.
This does not affect Ubuntu 5.10. (CVE-2006-5701)

An integer overflow was found in the get_fdb_entries() function of the
network bridging code. By executing a specially crafted ioctl, a local
attacker could exploit this to execute arbitrary code with root
privileges. (CVE-2006-5751)

Update instructions

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

Ubuntu 6.10:

linux-image-2.6.17-10-powerpc-smp 2.6.17.1-10.34

linux-image-2.6.17-10-386 2.6.17.1-10.34

linux-image-2.6.17-10-sparc64-smp 2.6.17.1-10.34

linux-image-2.6.17-10-sparc64 2.6.17.1-10.34

linux-image-2.6.17-10-generic 2.6.17.1-10.34

linux-image-2.6.17-10-powerpc 2.6.17.1-10.34

linux-image-2.6.17-10-server-bigiron 2.6.17.1-10.34

linux-image-2.6.17-10-powerpc64-smp 2.6.17.1-10.34

linux-image-2.6.17-10-server 2.6.17.1-10.34

Ubuntu 6.06 LTS:

linux-image-2.6.15-27-powerpc-smp 2.6.15-27.50

linux-image-2.6.15-27-amd64-xeon 2.6.15-27.50

linux-source-2.6.15 2.6.15-27.50

linux-image-2.6.15-27-k7 2.6.15-27.50

linux-image-2.6.15-27-sparc64 2.6.15-27.50

linux-image-2.6.15-27-686 2.6.15-27.50

linux-image-2.6.15-27-amd64-k8 2.6.15-27.50

linux-image-2.6.15-27-powerpc 2.6.15-27.50

linux-image-2.6.15-27-server-bigiron 2.6.15-27.50

linux-image-2.6.15-27-amd64-generic 2.6.15-27.50

linux-image-2.6.15-27-386 2.6.15-27.50

linux-image-2.6.15-27-powerpc64-smp 2.6.15-27.50

linux-image-2.6.15-27-sparc64-smp 2.6.15-27.50

linux-image-2.6.15-27-server 2.6.15-27.50

linux-image-2.6.15-27-amd64-server 2.6.15-27.50

Ubuntu 5.10:

linux-image-2.6.12-10-amd64-k8-smp 2.6.12-10.42

linux-image-2.6.12-10-686 2.6.12-10.42

linux-image-2.6.12-10-amd64-generic 2.6.12-10.42

linux-image-2.6.12-10-686-smp 2.6.12-10.42

linux-patch-ubuntu-2.6.12 2.6.12-10.42

linux-image-2.6.12-10-k7-smp 2.6.12-10.42

linux-image-2.6.12-10-amd64-k8 2.6.12-10.42

linux-image-2.6.12-10-sparc64-smp 2.6.12-10.42

linux-image-2.6.12-10-amd64-xeon 2.6.12-10.42

linux-image-2.6.12-10-k7 2.6.12-10.42

linux-image-2.6.12-10-sparc64 2.6.12-10.42

linux-image-2.6.12-10-powerpc 2.6.12-10.42

linux-image-2.6.12-10-386 2.6.12-10.42

linux-image-2.6.12-10-powerpc64-smp 2.6.12-10.42

linux-image-2.6.12-10-powerpc-smp 2.6.12-10.42

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system upgrade you need to reboot your computer to
effect the necessary changes.

References

CVE-2006-4572, CVE-2006-4813, CVE-2006-4997, CVE-2006-5158, CVE-2006-5173, CVE-2006-5619, CVE-2006-5648, CVE-2006-5649, CVE-2006-5701, CVE-2006-5751