# CVE-2022-4291: Aswjsflt.dll in Avast Antivirus windows caused a crash of the Mozilla Firefox browser due to heap corruption

> Heap corruption in Avast's aswjsflt.dll allows attackers to crash browsers and potentially bypass application sandboxes.

- **Severity:** High 7.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Dec 2022
- **Updated:** 14 Apr 2025
- **Also known as:** GHSA-m5gg-2gxj-3qqx

## What is CVE-2022-4291?

CVE-2022-4291 is a high-severity memory corruption vulnerability in NortonLifelock Avast Antivirus, published on 7 Dec 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The aswjsflt.dll library from Avast Antivirus windows contained a potentially exploitable heap corruption vulnerability that could enable an attacker to bypass the sandbox of the application it was loaded into, if applicable. This issue was fixed in version 18.0.1478 of the Script Shield Component.

Weakness: CWE-787 (Out-of-bounds Write), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2022-4291?

It affects 1 product.


Products: Avast Script Shield.

## How do I fix CVE-2022-4291?

No fix has been published for CVE-2022-4291 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-4291 being exploited?

There is no known exploitation of CVE-2022-4291 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-4291 and fix it if it is affected.

What it is: CVE-2022-4291 is a high-severity memory corruption vulnerability in NortonLifelock Avast Antivirus, published on 7 Dec 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-4291 in the wild and no public exploit code.

Affected product: NortonLifelock Avast Antivirus. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-4291/ (Markdown: https://insights.sbomify.com/CVE-2022-4291/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-4291
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-4291
- OSV: https://osv.dev/vulnerability/CVE-2022-4291

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-4291/
Summaries are generated and may contain mistakes; the official description above is the record.