Description:
An input validation vulnerability was reported in the Linux 2.4 kernel. A local user can gain root level privileges.
It is reported that the do_brk() function does not perform proper bounds checking. A local user can run a userland application to cause the kernel to grant the local user access to the full kernel address space. The userland application can create an arbitrary and large virtual memory area, exceeding user accessible memory limits (TASK_SIZE).
Red Hat reports that an exploit for this flaw has been found in the wild.
Impact:
A local user can gain root privileges.
Solution:
A fixed kernel version (2.4.23) is available.
Date: Mon, 01 Dec 2003 14:35:39 -0500 Subject: CAN-2003-0961
CAN-2003-0961
Red Hat reported:
> A flaw in bounds checking in the do_brk() function in the Linux kernel
> versions 2.4.22 and previous can allow a local attacker to gain root
> privileges. This issue is known to be exploitable; an exploit has been
> seen in the wild that takes advantage of this vulnerability.
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