MEDIUM
The nfs_permission function in fs/nfs/dir.c in the NFS client implementation in the Linux kernel 2.6.29.3 and earlier, when atomic_open is available, does not check execute (aka EXEC or MAY_EXEC) permission bits, which allows local users to bypass permissions and execute files, as demonstrated by files on an NFSv4 fileserver.
http://article.gmane.org/gmane.linux.nfs/26592
http://bugzilla.linux-nfs.org/show_bug.cgi?id=131
http://linux-nfs.org/pipermail/nfsv4/2006-November/005313.html
http://linux-nfs.org/pipermail/nfsv4/2006-November/005323.html
http://lists.opensuse.org/opensuse-security-announce/2009-06/msg00001.html
http://lists.opensuse.org/opensuse-security-announce/2009-07/msg00004.html
http://secunia.com/advisories/35106
http://secunia.com/advisories/35298
http://secunia.com/advisories/35394
http://secunia.com/advisories/35656
http://secunia.com/advisories/35847
http://secunia.com/advisories/36051
http://secunia.com/advisories/36327
http://secunia.com/advisories/37471
http://wiki.rpath.com/Advisories:rPSA-2009-0111
http://www.debian.org/security/2009/dsa-1809
http://www.debian.org/security/2009/dsa-1844
http://www.debian.org/security/2009/dsa-1865
http://www.mandriva.com/security/advisories?name=MDVSA-2009:135
http://www.mandriva.com/security/advisories?name=MDVSA-2009:148
http://www.openwall.com/lists/oss-security/2009/05/13/2
http://www.redhat.com/support/errata/RHSA-2009-1157.html
http://www.securityfocus.com/archive/1/505254/100/0/threaded
http://www.securityfocus.com/archive/1/507985/100/0/threaded
http://www.securityfocus.com/bid/34934
http://www.ubuntu.com/usn/usn-793-1
http://www.vmware.com/security/advisories/VMSA-2009-0016.html
http://www.vupen.com/english/advisories/2009/1331
http://www.vupen.com/english/advisories/2009/3316
https://bugzilla.redhat.com/show_bug.cgi?id=500297
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8543
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9990