CVE-2017-1000253 Information

Description

Linux distributions that have not patched their long-term kernels with https://git.kernel.org/linus/a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (committed on April 14 2015). This kernel vulnerability was fixed in April 2015 by commit a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (backported to Linux 3.10.77 in May 2015) but it was not recognized as a security threat. With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE enabled and a normal top-down address allocation strategy load_elf_binary() will attempt to map a PIE binary into an address range immediately below mm-mmap_base. Unfortunately load_elf_ binary() does not take account of the need to allocate sufficient space for the entire binary which means that while the first PT_LOAD segment is mapped below mm-mmap_base the subsequent PT_LOAD segment(s) end up being mapped above mm-mmap_base into the are that is supposed to be the \gap\ between the stack and the binary.

CVSS Vector

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

http://www.securityfocus.com/bid/101010 http://www.securitytracker.com/id/1039434 https://access.redhat.com/errata/RHSA-2017:2793 https://access.redhat.com/errata/RHSA-2017:2794 https://access.redhat.com/errata/RHSA-2017:2795 https://access.redhat.com/errata/RHSA-2017:2796 https://access.redhat.com/errata/RHSA-2017:2797 https://access.redhat.com/errata/RHSA-2017:2798 https://access.redhat.com/errata/RHSA-2017:2799 https://access.redhat.com/errata/RHSA-2017:2800 https://access.redhat.com/errata/RHSA-2017:2801 https://access.redhat.com/errata/RHSA-2017:2802 https://www.qualys.com/2017/09/26/cve-2017-1000253/cve-2017-1000253.txt

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8