CVE-2018-13405 – Linux (Ubuntu) - Other Users coredumps Can Be Read via setgid Directory and killpriv Bypass

https://notcve.org/view.php?id=CVE-2018-13405

The inode_init_owner function in fs/inode.c in the Linux kernel through 3.16 allows local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID. La función inode_init_owner en fs/inode.c en el kernel de Linux hasta la versión 3.16 permite a los usuarios locales crear archivos con una propiedad de grupo no deseada, en un escenario donde un directorio es SGID a un cierto grupo y es escribible por un usuario que no es miembro de ese grupo. • https://www.exploit-db.com/exploits/45033 http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0fa3ecd87848c9c93c2c828ef4c3a8ca36ce46c7 http://openwall.com/lists/oss-security/2018/07/13/2 http://www.securityfocus.com/bid/106503 https://access.redhat.com/errata/RHSA-2018:2948 https://access.redhat.com/errata/RHSA-2018:3083 https://access.redhat.com/errata/RHSA-2018:3096 https://access.redhat.com/errata/RHSA-2019:0717 https://access.redhat.com/errata/RHSA- • CWE-269: Improper Privilege Management CWE-284: Improper Access Control •