### [CVE-2021-3864](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3864)
![](https://img.shields.io/static/v1?label=Product&message=kernel&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=Not%20Known%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-284%20-%20Improper%20Access%20Control&color=brightgreen)

### Description

A flaw was found in the way the dumpable flag setting was handled when certain SUID binaries executed its descendants. The prerequisite is a SUID binary that sets real UID equal to effective UID, and real GID equal to effective GID. The descendant will then have a dumpable value set to 1. As a result, if the descendant process crashes and core_pattern is set to a relative value, its core dump is stored in the current directory with uid:gid permissions. An unprivileged local user with eligible root SUID binary could use this flaw to place core dumps into root-owned directories, potentially resulting in escalation of privileges.

### POC

#### Reference
- https://www.openwall.com/lists/oss-security/2021/10/20/2

#### Github
- https://github.com/ARPSyndicate/cvemon
- https://github.com/NaInSec/CVE-PoC-in-GitHub
- https://github.com/SYRTI/POC_to_review
- https://github.com/WhooAmii/POC_to_review
- https://github.com/bygregonline/devsec-fastapi-report
- https://github.com/k0mi-tg/CVE-POC
- https://github.com/lucasrod16/exploitlens
- https://github.com/manas3c/CVE-POC
- https://github.com/nomi-sec/PoC-in-GitHub
- https://github.com/robertsirc/sle-bci-demo
- https://github.com/shakyaraj9569/Documentation
- https://github.com/trhacknon/Pocingit
- https://github.com/walac/cve-2021-3864
- https://github.com/whoforget/CVE-POC
- https://github.com/youwizard/CVE-POC
- https://github.com/zecool/cve