cve/2023/CVE-2023-4577.md

### [CVE-2023-4577](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-4577)
![](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=unspecified%3C%20115.2%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Version&message=unspecified%3C%20117%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Memory%20corruption%20in%20JIT%20UpdateRegExpStatics&color=brighgreen)

### Description

When `UpdateRegExpStatics` attempted to access `initialStringHeap` it could already have been garbage collected prior to entering the function, which could potentially have led to an exploitable crash. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thunderbird < 115.2.

### POC

#### Reference
No PoCs from references.

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