CVEs-PoC/2021/CVE-2021-29964.md

### [CVE-2021-29964](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29964)
![](https://img.shields.io/static/v1?label=Product&message=Firefox%20ESR&color=blue)
![](https://img.shields.io/static/v1?label=Product&message=Firefox&color=blue)
![](https://img.shields.io/static/v1?label=Product&message=Thunderbird&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3C%2078.11%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Version&message=%3C%2089%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Out%20of%20bounds-read%20when%20parsing%20a%20%60WM_COPYDATA%60%20message&color=brighgreen)

### Description

A locally-installed hostile program could send `WM_COPYDATA` messages that Firefox would process incorrectly, leading to an out-of-bounds read. *This bug only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 78.11, Firefox < 89, and Firefox ESR < 78.11.

### POC

#### Reference
- https://bugzilla.mozilla.org/show_bug.cgi?id=1706501

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