The isdn_ioctl function in isdn_common.c in Linux kernel 2.6.23 allows local users to cause a denial of service via a crafted ioctl struct in which iocts is not null terminated, which triggers a buffer overflow.
WIND00158964.zip is for 1.4
WIND00158972.zip is for 1.5
1. Unzip the patch under [install_dir]/updates  
2. Install the patch CD by entering the patch CD directory and run setup_linux.  
3. This is a source only patch so you will have to build the kernel  
4. Issue a make fs and make the kernel in a configured directory.  
5. Upload the kernel and rootfs into the target and boot it up.