cve/2021/CVE-2021-29982.md

### [CVE-2021-29982](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29982)
![](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%2091%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Single%20bit%20data%20leak%20due%20to%20incorrect%20JIT%20optimization%20and%20type%20confusion&color=brighgreen)

### Description

Due to incorrect JIT optimization, we incorrectly interpreted data from the wrong type of object, resulting in the potential leak of a single bit of memory. This vulnerability affects Firefox < 91 and Thunderbird < 91.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/googleprojectzero/fuzzilli
- https://github.com/zhangjiahui-buaa/MasterThesis