### [CVE-2021-28040](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28040)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brightgreen)

### Description

An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation fault once unmapped memory is reached.

### POC

#### Reference
- https://github.com/ossec/ossec-hids/issues/1953

#### Github
- https://github.com/FUAZA/ECE9069_Presentation_2