VFS in the Linux kernel before 2.6.22.16, and 2.6.23.x before 2.6.23.14, performs tests of access mode by using the flag variable instead of the acc_mode variable, which might allow local users to bypass intended permissions and remove directories.

The tcp_sacktag_write_queue function in net/ipv4/tcp_input.c in Linux kernel 2.6.21 through 2.6.23.7, and 2.6.24-rc through 2.6.24-rc2, allows remote attackers to cause a denial of service (crash) via crafted ACK responses that trigger a NULL pointer dereference.