# CVE-2015-4495: Mozilla Firefox Security Feature Bypass Vulnerability

Source: https://junglewise.ai/threats/cve-2015-4495-mozilla-firefox-security-feature-bypass-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-05-25. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2015-4495 · Severity: critical · CVSS 8.8 · Exploited in the wild · Published 2022-05-25

The PDF reader in Mozilla Firefox allows remote attackers to bypass the Same Origin Policy (SOP) via crafted JavaScript code and a native setter. This vulnerability enables attackers to read arbitrary local files or gain elevated privileges, and was notably exploited in the wild to target sensitive user data.

Technologies: [Mozilla Firefox](https://junglewise.ai/threats/technologies/firefox), [Mozilla Firefox ESR](https://junglewise.ai/threats/technologies/firefox-esr), [Mozilla Thunderbird](https://junglewise.ai/threats/technologies/thunderbird). Vendors: [Mozilla](https://junglewise.ai/threats/vendors/mozilla).

## Quick answers

**Is CVE-2015-4495 exploited in the wild?** Yes. CVE-2015-4495 is known to be exploited in the wild, first recorded on 25 May 2022. Treat it as urgent.

**How severe is CVE-2015-4495?** Critical severity, with a CVSS score of 8.8, published 25 May 2022.

**Which products and versions are affected?** Mozilla Firefox before 39.0.3; Mozilla Firefox ESR 38.x before 38.1.1; Mozilla Firefox OS before 2.2.

**Is there a fix for CVE-2015-4495?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2015-4495 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2015-4495?** Check whether you run Mozilla Firefox, Mozilla Firefox ESR or Mozilla Thunderbird. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Mozilla Firefox before 39.0.3
- Mozilla Firefox ESR 38.x before 38.1.1
- Mozilla Firefox OS before 2.2

## Timeline

- 2015-08-06: disclosed: Exploit found in the wild reported by Mozilla blog
- 2015-08-01: exploited: Exploited in the wild in August 2015
- 2022-05-25: kev added: Added to CISA Known Exploited Vulnerabilities Catalog

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