Vulnerabilities > CVE-2019-17001 - Cross-site Scripting vulnerability in Mozilla Firefox 69.0

047910
CVSS 5.8 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
NONE
network
mozilla
CWE-79
nessus

Summary

A Content-Security-Policy that blocks in-line scripts could be bypassed using an object tag to execute JavaScript in the protected document (cross-site scripting). This is a separate bypass from CVE-2019-17000.*Note: This flaw only affected Firefox 69 and was not present in earlier versions.*. This vulnerability affects Firefox < 70.

Vulnerable Configurations

Part Description Count
Application
Mozilla
1

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Embedding Scripts in Non-Script Elements
    This attack is a form of Cross-Site Scripting (XSS) where malicious scripts are embedded in elements that are not expected to host scripts such as image tags (<img>), comments in XML documents (< !-CDATA->), etc. These tags may not be subject to the same input validation, output validation, and other content filtering and checking routines, so this can create an opportunity for an attacker to tunnel through the application's elements and launch a XSS attack through other elements. As with all remote attacks, it is important to differentiate the ability to launch an attack (such as probing an internal network for unpatched servers) and the ability of the remote attacker to collect and interpret the output of said attack.
  • Embedding Scripts within Scripts
    An attack of this type exploits a programs' vulnerabilities that are brought on by allowing remote hosts to execute scripts. The attacker leverages this capability to execute scripts to execute his/her own script by embedding it within other scripts that the target software is likely to execute. The attacker must have the ability to inject script into script that is likely to be executed. If this is done, then the attacker can potentially launch a variety of probes and attacks against the web server's local environment, in many cases the so-called DMZ, back end resources the web server can communicate with, and other hosts. With the proliferation of intermediaries, such as Web App Firewalls, network devices, and even printers having JVMs and Web servers, there are many locales where an attacker can inject malicious scripts. Since this attack pattern defines scripts within scripts, there are likely privileges to execute said attack on the host. Of course, these attacks are not solely limited to the server side, client side scripts like Ajax and client side JavaScript can contain malicious scripts as well. In general all that is required is for there to be sufficient privileges to execute a script, but not protected against writing.
  • Cross-Site Scripting in Error Pages
    An attacker distributes a link (or possibly some other query structure) with a request to a third party web server that is malformed and also contains a block of exploit code in order to have the exploit become live code in the resulting error page. When the third party web server receives the crafted request and notes the error it then creates an error message that echoes the malformed message, including the exploit. Doing this converts the exploit portion of the message into to valid language elements that are executed by the viewing browser. When a victim executes the query provided by the attacker the infected error message error message is returned including the exploit code which then runs in the victim's browser. XSS can result in execution of code as well as data leakage (e.g. session cookies can be sent to the attacker). This type of attack is especially dangerous since the exploit appears to come from the third party web server, who the victim may trust and hence be more vulnerable to deception.
  • Cross-Site Scripting Using Alternate Syntax
    The attacker uses alternate forms of keywords or commands that result in the same action as the primary form but which may not be caught by filters. For example, many keywords are processed in a case insensitive manner. If the site's web filtering algorithm does not convert all tags into a consistent case before the comparison with forbidden keywords it is possible to bypass filters (e.g., incomplete black lists) by using an alternate case structure. For example, the "script" tag using the alternate forms of "Script" or "ScRiPt" may bypass filters where "script" is the only form tested. Other variants using different syntax representations are also possible as well as using pollution meta-characters or entities that are eventually ignored by the rendering engine. The attack can result in the execution of otherwise prohibited functionality.

Nessus

  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-4165-1.NASL
    descriptionMultiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, bypass security restrictions, bypass same-origin restrictions, conduct cross-site scripting (XSS) attacks, bypass content security policy (CSP) protections, or execute arbitrary code. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-06-01
    modified2020-06-02
    plugin id130200
    published2019-10-24
    reporterUbuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/130200
    titleUbuntu 16.04 LTS / 18.04 LTS / 19.04 / 19.10 : firefox vulnerabilities (USN-4165-1)
  • NASL familyWindows
    NASL idMOZILLA_FIREFOX_70_0.NASL
    descriptionThe version of Firefox installed on the remote Windows host is prior to 70.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2019-34 advisory, including the following: - Incorrect derivation of a packet length in WebRTC in Google Chrome prior to 68.0.3440.75 allowed a remote attacker to potentially exploit heap corruption via a crafted video file. (CVE-2018-6156) - In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a consecutive call to XML_GetCurrentLineNumber (or XML_GetCurrentColumnNumber) then resulted in a heap-based buffer over-read. (CVE-2019-15903) - When storing a value in IndexedDB, the value
    last seen2020-06-01
    modified2020-06-02
    plugin id130170
    published2019-10-24
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/130170
    titleMozilla Firefox < 70.0 Multiple Vulnerabilities
  • NASL familyMacOS X Local Security Checks
    NASL idMACOS_FIREFOX_70_0.NASL
    descriptionThe version of Firefox installed on the remote macOS or Mac OS X host is prior to 70.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2019-34 advisory, including the following: - Incorrect derivation of a packet length in WebRTC in Google Chrome prior to 68.0.3440.75 allowed a remote attacker to potentially exploit heap corruption via a crafted video file. (CVE-2018-6156) - In libexpat before 2.2.8, crafted XML input could fool the parser into changing from DTD parsing to document parsing too early; a consecutive call to XML_GetCurrentLineNumber (or XML_GetCurrentColumnNumber) then resulted in a heap-based buffer over-read. (CVE-2019-15903) - When storing a value in IndexedDB, the value
    last seen2020-06-01
    modified2020-06-02
    plugin id130169
    published2019-10-24
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/130169
    titleMozilla Firefox < 70.0 Multiple Vulnerabilities