cve/2017/CVE-2017-1000253.md

### [CVE-2017-1000253](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-1000253)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### 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.

### POC

#### Reference
- https://www.qualys.com/2017/09/26/cve-2017-1000253/cve-2017-1000253.txt

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/JlSakuya/Linux-Privilege-Escalation-Exploits
- https://github.com/RicterZ/PIE-Stack-Clash-CVE-2017-1000253
- https://github.com/kaosagnt/ansible-everyday
- https://github.com/sxlmnwb/CVE-2017-1000253