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)
14 December 2006
A security issue affects these releases of Ubuntu and its derivatives:
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)
The problem can be corrected by updating your system to the following package versions:
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.
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