cve/2021/CVE-2021-21781.md

### [CVE-2021-21781](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21781)
![](https://img.shields.io/static/v1?label=Product&message=Linux%20Kernel&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=Linux%20Kernel%20v5.4.54%2C%20Linux%20Kernel%20v5.4.66%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-908%3A%20Use%20of%20Uninitialized%20Resource&color=brightgreen)

### Description

An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. A userland application can read the contents of the sigpage, which can leak kernel memory contents. An attacker can read a process’s memory at a specific offset to trigger this vulnerability. This was fixed in kernel releases: 4.14.222 4.19.177 5.4.99 5.10.17 5.11

### POC

#### Reference
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1243
- https://www.oracle.com/security-alerts/cpujul2022.html

#### Github
No PoCs found on GitHub currently.