Mozilla Firefox 41 Reader Mode Content Security Policy cross site scripting

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.

A vulnerability was found in Mozilla Firefox 41 (Web Browser). It has been declared as critical. Affected by this vulnerability is an unknown code of the component Reader Mode. The manipulation with an unknown input leads to a cross site scripting vulnerability (Content Security Policy). The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was disclosed 11/03/2015 as MFSA 2015-11 as confirmed security advisory (Website). It is possible to read the advisory at This vulnerability is known as CVE-2015-4518 since 06/10/2015. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 86955 (FreeBSD : mozilla -- multiple vulnerabilities (9d04936c-75f1-4a2c-9ade-4c1708be5df9)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FreeBSD Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 168223 (OpenSuSE Security Update for MozillaFirefox, mozilla-nspr, (openSUSE-SU-2015:1942-1)).

Upgrading eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at X-Force (107792) and Tenable (86955). The entries 69222, 69223, 78498 and 79024 are pretty similar.







CPE 2.3info

CPE 2.2info


VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍


VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 8.5

VulDB Base Score: 9.8
VulDB Temp Score: 8.5
VulDB Vector: 🔍
VulDB Reliability: 🔍



VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍


Name: Content Security Policy
Class: Cross site scripting / Content Security Policy
CWE: CWE-79 / CWE-74 / CWE-707
ATT&CK: T1059.007

Local: No
Remote: Yes

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Nessus ID: 86955
Nessus Name: FreeBSD : mozilla -- multiple vulnerabilities (9d04936c-75f1-4a2c-9ade-4c1708be5df9)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 803059
OpenVAS Name: Mozilla Firefox Multiple Vulnerabilities - Nov15 (Windows)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍


06/10/2015 🔍
11/03/2015 +146 days 🔍
11/03/2015 +0 days 🔍
11/03/2015 +0 days 🔍
11/04/2015 +1 days 🔍
11/04/2015 +0 days 🔍
11/05/2015 +1 days 🔍
11/20/2015 +15 days 🔍
06/26/2022 +2410 days 🔍



Advisory: MFSA 2015-11
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2015-4518 (🔍)
X-Force: 107792 - Mozilla Firefox Reader mode security bypass
SecurityTracker: 1034069
Vulnerability Center: 54168 - Mozilla Firefox before 42 Remote XSS via CSP Protections - CVE-2015-4518, Medium
SecurityFocus: 77412

See also: 🔍


Created: 11/04/2015 11:09 AM
Updated: 06/26/2022 09:05 AM
Changes: 11/04/2015 11:09 AM (57), 03/10/2018 11:46 AM (19), 06/26/2022 09:05 AM (4)
Complete: 🔍


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