Default fonts on OS X display some Tibetan characters as whitespace. When used in the addressbar as part of an IDN this can be used for domain name spoofing attacks. Note: This attack only affects OS X operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.

WebExtensions could use popups and panels in the extension UI to load an "about:" privileged URL, violating security checks that disallow this behavior. This vulnerability affects Firefox < 56.

A mechanism where when a new tab is loaded through JavaScript events, if fullscreen mode is then entered, the addressbar will not be rendered. This would allow a malicious site to displayed a spoofed addressbar, showing the location of an arbitrary website instead of the one loaded. Note: this issue only affects Firefox for Android. Desktop Firefox is unaffected. This vulnerability affects Firefox < 54.

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.

On pages containing an iframe, the "data:" protocol can be used to create a modal alert that will render over arbitrary domains following page navigation, spoofing of the origin of the modal alert from the iframe content. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

A mechanism that uses AppCache to hijack a URL in a domain using fallback by serving the files from a sub-path on the domain. This has been addressed by requiring fallback files be inside the manifest directory. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

On Windows systems, the logger run by the Windows updater deletes the file "update.log" before it runs in order to write a new log of that name. The path to this file is supplied at the command line to the updater and could be used in concert with another local exploit to delete a different file named "update.log" instead of the one intended. Note: This attack only affects Windows operating systems. Other operating systems are not affected. This vulnerability affects Firefox < 55.

Characters from the "Canadian Syllabics" unicode block can be mixed with characters from other unicode blocks in the addressbar instead of being rendered as their raw "punycode" form, allowing for domain name spoofing attacks through character confusion. The current Unicode standard allows characters from "Aspirational Use Scripts" such as Canadian Syllabics to be mixed with Latin characters in the "moderately restrictive" IDN profile. We have changed Firefox behavior to match the upcoming Unicode version 10.0 which removes this category and treats them as "Limited Use Scripts.". This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.

When entered directly, Reader Mode did not strip the username and password section of URLs displayed in the addressbar. This can be used for spoofing the domain of the current page. This vulnerability affects Firefox < 54.

On pages containing an iframe, the "data:" protocol can be used to create a modal dialog through Javascript that will have an arbitrary domains as the dialog's location, spoofing of the origin of the modal dialog from the user view. Note: This attack only affects installations with e10 multiprocess turned off. Installations with e10s turned on do not support the modal dialog functionality. This vulnerability affects Firefox < 56.

If a long user name is used in a username/password combination in a site URL (such as " http://UserName:Password@example.com"), the resulting modal prompt will hang in a non-responsive state or crash, causing a denial of service. This vulnerability affects Firefox < 55.

SVG loaded through "<img>" tags can use "<meta>" tags within the SVG data to set cookies for that page. This vulnerability affects Firefox < 57.

Bugzilla 2.x and 3.x before 3.4.14, 3.5.x and 3.6.x before 3.6.8, 3.7.x and 4.0.x before 4.0.4, and 4.1.x and 4.2.x before 4.2rc2 does not reject non-ASCII characters in e-mail addresses of new user accounts, which makes it easier for remote authenticated users to spoof other user accounts by choosing a similar e-mail address.

The nsWindow implementation in the browser engine in Mozilla Firefox before 3.6.28 and 4.x through 10.0, Firefox ESR 10.x before 10.0.3, Thunderbird before 3.1.20 and 5.0 through 10.0, Thunderbird ESR 10.x before 10.0.3, and SeaMonkey before 2.8 does not check the validity of an instance after event dispatching, which allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown vectors, as demonstrated by Mobile Firefox on Android.

A mechanism to spoof the addressbar through the user interaction on the addressbar and the "onblur" event. The event could be used by script to affect text display to make the loaded site appear to be different from the one actually loaded within the addressbar. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 52.1, and Firefox < 53.

Insufficient bounds checking of data during inter-process communication might allow a compromised content process to be able to read memory from the parent process under certain conditions. This vulnerability affects Firefox < 66.

When arbitrary text is sent over an FTP connection and a page reload is initiated, it is possible to create a modal alert message with this text as the content. This could potentially be used for social engineering attacks. This vulnerability affects Firefox < 66.

A possibly exploitable crash triggered during layout and manipulation of bidirectional unicode text in concert with CSS animations. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 52.1, and Firefox < 53.

Malicious sites can display a spoofed addressbar on a page when the existing location bar on the new page is scrolled out of view if an HTML editable page element is user selected. Note: This attack only affects Firefox for Android. Other operating systems are not affected. This vulnerability affects Firefox < 53.

An attack can use a blob URL and script to spoof an arbitrary addressbar URL prefaced by "blob:" as the protocol, leading to user confusion and further spoofing attacks. This vulnerability affects Firefox < 52.

When dragging content from the primary browser pane to the addressbar on a malicious site, it is possible to change the addressbar so that the displayed location following navigation does not match the URL of the newly loaded page. This allows for spoofing attacks. This vulnerability affects Firefox < 52.

A "javascript:" url loaded by a malicious page can obfuscate its location by blanking the URL displayed in the addressbar, allowing for an attacker to spoof an existing page without the malicious page's address being displayed correctly. This vulnerability affects Firefox < 52.

URLs containing certain unicode glyphs for alternative hyphens and quotes do not properly trigger punycode display, allowing for domain name spoofing attacks in the location bar. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

Android intents can be used to launch Firefox for Android in reader mode with a user specified URL. This allows an attacker to spoof the contents of the addressbar as displayed to users. Note: This attack only affects Firefox for Android. Other operating systems are not affected. This vulnerability affects Firefox < 53.

A mechanism to spoof the Firefox for Android addressbar using a "javascript:" URI. On Firefox for Android, the base domain is parsed incorrectly, making the resulting location less visibly a spoofed site and showing an incorrect domain in appended notifications. This vulnerability affects Firefox < 53.

A malicious site could spoof the contents of the print preview window if popup windows are enabled, resulting in user confusion of what site is currently loaded. This vulnerability affects Firefox < 52 and Thunderbird < 52.

A mechanism to inject static HTML into the RSS reader preview page due to a failure to escape characters sent as URL parameters for a feed's "TITLE" element. This vulnerability allows for spoofing but no scripted content can be run. This vulnerability affects Firefox < 53.

Malicious sites can display a spoofed location bar on a subsequently loaded page when the existing location bar on the new page is scrolled out of view if navigations between pages can be timed correctly. Note: This issue only affects Firefox for Android. Other operating systems are not affected. This vulnerability affects Firefox < 51.

The JSSubScriptLoader in Mozilla Firefox before 3.6.24 and Thunderbird before 3.1.6 does not properly handle XPCNativeWrappers during calls to the loadSubScript method in an add-on, which makes it easier for remote attackers to gain privileges via a crafted web site that leverages certain unwrapping behavior, a related issue to CVE-2011-3004.

The JSSubScriptLoader in Mozilla Firefox 4.x through 6 and SeaMonkey before 2.4 does not properly handle XPCNativeWrappers during calls to the loadSubScript method in an add-on, which makes it easier for remote attackers to gain privileges via a crafted web site that leverages certain unwrapping behavior.

Mozilla Gecko before 5.0, as used in Firefox before 5.0 and Thunderbird before 5.0, does not block use of a cross-domain image as a WebGL texture, which allows remote attackers to obtain approximate copies of arbitrary images via a timing attack involving a crafted WebGL fragment shader.

In Network Security Services (NSS) before 3.46, several cryptographic primitives had missing length checks. In cases where the application calling the library did not perform a sanity check on the inputs it could result in a crash due to a buffer overflow.

Until explicitly accessed by script, window.globalThis is not enumerable and, as a result, is not visible to code such as Object.getOwnPropertyNames(window). Sites that deploy a sandboxing that depends on enumerating and freezing access to the window object may miss this, allowing their sandboxes to be bypassed. This vulnerability affects Firefox < 68.

Necko can access a child on the wrong thread during UDP connections, resulting in a potentially exploitable crash in some instances. This vulnerability affects Firefox < 68.

Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxed parent process opening web content chosen by a compromised child process. When combined with additional vulnerabilities this could result in executing arbitrary code on the user's computer. This vulnerability affects Firefox ESR < 60.7.2, Firefox < 67.0.4, and Thunderbird < 60.7.2.

The combined, single character, version of the letter 'i' with any of the potential accents in unicode, such as acute or grave, can be spoofed in the addressbar by the dotless version of 'i' followed by the same accent as a second character with most font sets. This allows for domain spoofing attacks because these combined domain names do not display as punycode. This vulnerability affects Firefox < 57.

The filename appearing in the "Downloads" panel improperly renders some Unicode characters, allowing for the file name to be spoofed. This can be used to obscure the file extension of potentially executable files from user view in the panel. Note: the dialog to open the file will show the full, correct filename and whether it is executable or not. This vulnerability affects Firefox < 60.

When packets with a mismatched RTP payload type are sent in WebRTC connections, in some circumstances a potentially exploitable crash is triggered. This vulnerability affects Firefox ESR < 52.7 and Firefox < 59.

A spoofing vulnerability can occur when a malicious site with an extremely long domain name is opened in an Android Custom Tab (a browser panel inside another app) and the default browser is Firefox for Android. This could allow an attacker to spoof which page is actually loaded and in use. Note: this issue only affects Firefox for Android. Other versions and operating systems are unaffected. This vulnerability affects Firefox < 59.

Mozilla Firefox before 3.5.19 and 3.6.x before 3.6.17, and SeaMonkey before 2.0.14, does not properly use nsTreeRange data structures, which allows remote attackers to execute arbitrary code via unspecified vectors that lead to a "dangling pointer."

If cursor visibility is toggled by script using from 'none' to an image and back through script, the cursor will be rendered temporarily invisible within Firefox. Note: This vulnerability only affects OS X. Other operating systems are not affected. This vulnerability affects Firefox < 58.

Mozilla Firefox before 3.5.17 and 3.6.x before 3.6.14, and SeaMonkey before 2.0.12, does not properly handle certain recursive eval calls, which makes it easier for remote attackers to force a user to respond positively to a dialog question, as demonstrated by a question about granting privileges.

The JSON Viewer displays clickable hyperlinks for strings that are parseable as URLs, including "javascript:" links. If a JSON file contains malicious JavaScript script embedded as "javascript:" links, users may be tricked into clicking and running this code in the context of the JSON Viewer. This can allow for the theft of cookies and authorization tokens which are accessible to that context. This vulnerability affects Firefox < 60.

It is possible to spoof the filename of an attachment and display an arbitrary attachment name. This could lead to a user opening a remote attachment which is a different file type than expected. This vulnerability affects Thunderbird ESR < 52.8 and Thunderbird < 52.8.

The X.509 certificate validation functionality in Mozilla Firefox 4.0.x through 4.0.1 does not properly implement single-session security exceptions, which might make it easier for user-assisted remote attackers to spoof an SSL server via an untrusted certificate that triggers potentially unwanted local caching of documents from that server.

A shared worker created from a "data:" URL in one tab can be shared by another tab with a different origin, bypassing the same-origin policy. This vulnerability affects Firefox < 59.

If manipulated hyperlinked text with "chrome:" URL contained in it is dragged and dropped on the "home" icon, the home page can be reset to include a normally-unlinkable chrome page as one of the home page tabs. This vulnerability affects Firefox < 60.