Oleg Nesterov discovered a local Denial of Service vulnerability in the timer handling. When a non group-leader thread called exec() to execute a different program while an itimer was pending, the timer expiry would signal the old group leader task, which did not exist any more. This caused a kernel panic. This vulnerability only affects Ubuntu 5.04. (CAN-2005-1913)
Al Viro discovered that the sendmsg() function did not sufficiently validate its input data. By calling sendmsg() and at the same time modifying the passed message in another thread, he could exploit this to execute arbitrary commands with kernel privileges. This only affects the amd64 bit platform. (CAN-2005-2490)
9 September 2005
A security issue affects these releases of Ubuntu and its derivatives:
Oleg Nesterov discovered a local Denial of Service vulnerability in the timer handling. When a non group-leader thread called exec() to execute a different program while an itimer was pending, the timer expiry would signal the old group leader task, which did not exist any more. This caused a kernel panic. This vulnerability only affects Ubuntu 5.04. (CAN-2005-1913)
Al Viro discovered that the sendmsg() function did not sufficiently validate its input data. By calling sendmsg() and at the same time modifying the passed message in another thread, he could exploit this to execute arbitrary commands with kernel privileges. This only affects the amd64 bit platform. (CAN-2005-2490)
Al Viro discovered a vulnerability in the raw_sendmsg() function. By calling this function with specially crafted arguments, a local attacker could either read kernel memory contents (leading to information disclosure) or manipulate the hardware state by reading certain IO ports. This vulnerability only affects Ubuntu 5.04. (CAN-2005-2492)
Jan Blunck discovered a Denial of Service vulnerability in the procfs interface of the SCSI driver. By repeatedly reading /proc/scsi/sg/devices, a local attacker could eventually exhaust kernel memory. (CAN-2005-2800)
A flaw was discovered in the handling of extended attributes on ext2 and ext3 file systems. Under certain condidions, this could prevent the enforcement of Access Control Lists, which eventually could lead to information disclosure, unauthorized program execution, or unauthorized data modification. This does not affect the standard Unix permissions. (CAN-2005-2801)
Chad Walstrom discovered a Denial of Service in the ipt_recent module, which can be used in netfilter (Firewall configuration). A remote attacker could exploit this to crash the kernel by sending certain packets (such as an SSH brute force attack) to a host which uses the “recent” module. (CAN-2005-2802)
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.
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