Linux kernel 2.4.x and 2.6.x up to 2.6.16 allows local users to bypass IPC permissions and modify a readonly attachment of shared memory by using mprotect to give write permission to the attachment. NOTE: some original raw sources combined this issue with CVE-2006-1524, but they are different bugs.

madvise_remove in Linux kernel 2.6.16 up to 2.6.16.6 does not follow file and mmap restrictions, which allows local users to bypass IPC permissions and replace portions of readonly tmpfs files with zeroes, aka the MADV_REMOVE vulnerability. NOTE: this description was originally written in a way that combined two separate issues. The mprotect issue now has a separate name, CVE-2006-2071.