The do_splice_from function in fs/splice.c in the Linux kernel before 2.6.27 does not reject file descriptors that have the O_APPEND flag set, which allows local users to bypass append mode and make arbitrary changes to other locations in the file.
git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.26.y.git%3Ba=commit%3Bh=efc968d450e013049a662d22727cf132618dcb2f
lists.opensuse.org/opensuse-security-announce/2009-06/msg00000.html
secunia.com/advisories/32386
secunia.com/advisories/32918
secunia.com/advisories/32998
secunia.com/advisories/33180
secunia.com/advisories/33182
secunia.com/advisories/33586
secunia.com/advisories/35390
www.debian.org/security/2008/dsa-1681
www.debian.org/security/2008/dsa-1687
www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.27
www.mandriva.com/security/advisories?name=MDVSA-2008:224
www.openwall.com/lists/oss-security/2008/10/13/1
www.openwall.com/lists/oss-security/2008/10/14/5
www.redhat.com/support/errata/RHSA-2008-1017.html
www.redhat.com/support/errata/RHSA-2009-0009.html
www.securityfocus.com/bid/31903
www.ubuntu.com/usn/usn-679-1
bugzilla.redhat.com/show_bug.cgi?id=466707
exchange.xforce.ibmcloud.com/vulnerabilities/45954
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11142
www.redhat.com/archives/fedora-package-announce/2008-October/msg00689.html
www.redhat.com/archives/fedora-package-announce/2008-October/msg00693.html