Note that the severity of this issue is lower than the similar issue that was discovered in overlayfs since the aufs module has to be loaded with the 'allow_userns' parameter.
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1547400 Title: aufs fails to handle sanitize xattrs in workdir, copies SUID binaries from no-suid fuse mounts Status in Linux: Confirmed Status in linux package in Ubuntu: Confirmed Bug description: When aufs module is loaded with "modprobe aufs allow_userns", unprivileged user can use xattrs on the working directory or aufs mount over a fuse mount to create SUID/SGID binaries, thus escalating privileges. These errors are quite similar to those on overlayfs: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1535150 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1534961 aufs developers have already confirmed and issued a fix: https://sourceforge.net/p/aufs/mailman/message/34864744/ Specific reproducers can be found at: http://www.halfdog.net/Security/2016/AufsPrivilegeEscalationInUserNamespaces/ InvitedOnly AkgY8iqF # lsb_release -rd Description: Ubuntu 15.10 Release: 15.10 # apt-cache policy linux-image-4.2.0-27-generic linux-image-4.2.0-27-generic: Installed: 4.2.0-27.32 Candidate: 4.2.0-27.32 Version table: *** 4.2.0-27.32 0 500 http://archive.ubuntu.com/ubuntu/ wily-updates/main amd64 Packages 500 http://archive.ubuntu.com/ubuntu/ wily-security/main amd64 Packages 100 /var/lib/dpkg/status To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1547400/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
