jail.c in jail in FreeBSD 8.0 and 8.1-PRERELEASE, when the "-l -U root" options are omitted, does not properly restrict access to the curre…

jail.c in jail in FreeBSD 8.0 and 8.1-PRERELEASE, when the "-l -U root" options are omitted, does not properly restrict access to the current working directory, which might allow local users to read, modify, or create arbitrary files via standard filesystem operations.