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.

The content security policy (CSP) "sandbox" directive did not create a unique origin for the document, causing it to behave as if the "allow-same-origin" keyword were always specified. This could allow a Cross-Site Scripting (XSS) attack to be launched from unsafe content. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

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.

If a page is loaded from an original site through a hyperlink and contains a redirect to a "data:text/html" URL, triggering a reload will run the reloaded "data:text/html" page with its origin set incorrectly. This allows for a cross-site scripting (XSS) attack. 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.

When a "javascript:" URL is drag and dropped by a user into the addressbar, the URL will be processed and executed. This allows for users to be socially engineered to execute an XSS attack on themselves. 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.

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.

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.

The "mozAddonManager" allows for the installation of extensions from the CDN for addons.mozilla.org, a publicly accessible site. This could allow malicious extensions to install additional extensions from the CDN in combination with an XSS attack on Mozilla AMO sites. This vulnerability affects Firefox < 51.

In certain scenarios a malicious website could attempt to display a fake location URL bar which could mislead users as to the actual website address This vulnerability affects Firefox for iOS < 127.

Due to an error while parsing page content, it is possible for properly sanitized user input to be misinterpreted and lead to XSS hazards on web sites in certain circumstances. This vulnerability affects Firefox ESR < 60.8, Firefox < 68, and Thunderbird < 60.8.

Hubs Cloud allows users to download shared content, specifically HTML and JS, which could allow javascript execution in the Hub Cloud instance’s primary hosting domain.*. This vulnerability affects Hubs Cloud < mozillareality/reticulum/1.0.1/20210618012634.

Cross-site scripting (XSS) vulnerability in the dependency graphs in Bugzilla 2.16rc1 through 4.4.11, and 4.5.1 through 5.0.2 allows remote attackers to inject arbitrary web script or HTML.

Address bar search suggestions in private browsing mode were re-using session data from normal mode. *This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 89.

Mozilla Firefox before 47.0 allows remote attackers to bypass the Same Origin Policy and modify the location.host property via an invalid data: URL.

Mozilla Firefox before 47.0 ignores Content Security Policy (CSP) directives for cross-domain Java applets, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted applet.

Lack of escaping allowed HTML injection when a webpage was viewed in Reader View. While a Content Security Policy prevents direct code execution, HTML injection is still possible. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 88.

Under certain circumstances, a JavaScript alert (or prompt) could have been shown while another website was displayed underneath it. This could have been abused to trick the user. <br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 97.

The WebExtension sandbox feature in browser/components/extensions/ext-tabs.js in Mozilla Firefox before 46.0 does not properly restrict principal inheritance during chrome.tabs.create and chrome.tabs.update API calls, which allows remote attackers to conduct Universal XSS (UXSS) attacks via a crafted extension that accesses a (1) javascript: or (2) data: URL.

An attacker could cause a select dropdown to be shown over another tab; this could have led to user confusion and possible spoofing attacks. This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.

Mozilla Firefox before 46.0 allows remote attackers to bypass the Content Security Policy (CSP) protection mechanism via the multipart/x-mixed-replace content type.

Mozilla Firefox before 47.0 allows remote attackers to spoof permission notifications via a crafted web site that rapidly triggers permission requests, as demonstrated by the microphone permission or the geolocation permission.

The Firefox Health Reports (aka FHR or about:healthreport) feature in Mozilla Firefox before 46.0 does not properly restrict the origin of events, which makes it easier for remote attackers to modify sharing preferences by leveraging access to the remote-report IFRAME element.

Firefox for Android could get stuck in fullscreen mode and not exit it even after normal interactions that should cause it to exit. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 91.

Mozilla Firefox before 47.0 and Firefox ESR 45.x before 45.2 allow remote attackers to spoof the address bar via a SELECT element with a persistent menu.

Mozilla Firefox before 44.0 allows user-assisted remote attackers to spoof a trailing substring in the address bar by leveraging a user's paste of a (1) wyciwyg: URI or (2) resource: URI.

CRLF injection vulnerability in Mozilla Firefox 4.x through 10.0, Firefox ESR 10.x before 10.0.3, Thunderbird 5.0 through 10.0, Thunderbird ESR 10.x before 10.0.3, and SeaMonkey before 2.8 allows remote web servers to bypass intended Content Security Policy (CSP) restrictions and possibly conduct cross-site scripting (XSS) attacks via crafted HTTP headers.

The file-download dialog in Mozilla Firefox before 44.0 on OS X enables a certain button too quickly, which allows remote attackers to conduct clickjacking attacks via a crafted web site that triggers a single-click action in a situation where a double-click action was intended.

Mozilla Firefox 43.x mishandles attempts to connect to the Application Reputation service, which makes it easier for remote attackers to trigger an unintended download by leveraging the absence of reputation data.

Mozilla Firefox before 45.0 and Firefox ESR 38.x before 38.7 mishandle a navigation sequence that returns to the original page, which allows remote attackers to spoof the address bar via vectors involving the history.back method and the location.protocol property.

The protocol-handler dialog in Mozilla Firefox before 44.0 allows remote attackers to conduct clickjacking attacks via a crafted web site that triggers a single-click action in a situation where a double-click action was intended.

browser/base/content/browser.js in Mozilla Firefox before 45.0 and Firefox ESR 38.x before 38.7 allows remote attackers to spoof the address bar via a javascript: URL.

Mozilla Firefox before 44.0 on Android does not ensure that HTTPS is used for a lightweight-theme installation, which allows man-in-the-middle attackers to replace a theme's images and colors by modifying the client-server data stream.

Mozilla Firefox before 44.0 on Android allows remote attackers to spoof the address bar via the scrollTo method.

Through a series of DOM manipulations, a message, over which the attacker had control of the text but not HTML or formatting, could be overlaid on top of another domain (with the new domain correctly shown in the address bar) resulting in possible user confusion. This vulnerability affects Firefox < 90.

Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilized non-HTTP schemes used internally by the Firefox iOS client. This vulnerability was fixed in Firefox for iOS 139.

When styling and rendering an oversized `<select>` element, Firefox did not apply correct clipping which allowed an attacker to paint over the user interface. This vulnerability affects Firefox < 89.

If a MIME encoded email contains an OpenPGP inline signed or encrypted message part, but also contains an additional unprotected part, Thunderbird did not indicate that only parts of the message are protected. This vulnerability affects Thunderbird < 78.10.2.

When network partitioning was enabled, e.g. as a result of Enhanced Tracking Protection settings, a TLS error page would allow the user to override an error on a domain which had specified HTTP Strict Transport Security (which implies that the error should not be override-able.) This issue did not affect the network connections, and they were correctly upgraded to HTTPS automatically. This vulnerability affects Firefox < 90.

When viewing an email message A, which contains an attached message B, where B is encrypted or digitally signed or both, Thunderbird may show an incorrect encryption or signature status. After opening and viewing the attached message B, when returning to the display of message A, the message A might be shown with the security status of message B. This vulnerability affects Thunderbird < 91.9.

Mozilla Network Security Services (NSS) before 3.20.2, as used in Mozilla Firefox before 43.0.2 and Firefox ESR 38.x before 38.5.2, does not reject MD5 signatures in Server Key Exchange messages in TLS 1.2 Handshake Protocol traffic, which makes it easier for man-in-the-middle attackers to spoof servers by triggering a collision.

Cross-site scripting (XSS) vulnerability in the internationalization feature in the default homescreen app in Mozilla Firefox OS before 2.5 allows user-assisted remote attackers to inject arbitrary web script or HTML via a crafted web site that is mishandled during "Add to home screen" bookmarking.

Mozilla Firefox before 42.0 on Android improperly restricts URL strings in intents, which allows attackers to conduct cross-site scripting (XSS) attacks via vectors involving an intent: URL and fallback navigation, aka "Universal XSS (UXSS)."

The Add-on SDK in Mozilla Firefox before 42.0 misinterprets a "script: false" panel setting, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via inline JavaScript code that is executed within a third-party extension.

Mozilla Firefox before 42.0 on Android does not ensure that the address bar is restored upon fullscreen-mode exit, which allows remote attackers to spoof the address bar via crafted JavaScript code.

An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent. If an attacker creates a crafted OpenPGP key with a subkey that has an invalid self signature, and the Thunderbird user imports the crafted key, then Thunderbird may try to use the invalid subkey, but the RNP library rejects it from being used, causing encryption to fail. This vulnerability affects Thunderbird < 78.9.1.

By utilizing 3D CSS in conjunction with Javascript, content could have been rendered outside the webpage's viewport, resulting in a spoofing attack that could have been used for phishing or other attacks on a user. This vulnerability affects Firefox < 88.

Using techniques that built on the slipstream research, a malicious webpage could have scanned both an internal network's hosts as well as services running on the user's local machine utilizing WebRTC connections. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

The developer page about:memory has a Measure function for exploring what object types the browser has allocated and their sizes. When this function was invoked we incorrectly called the sizeof function, instead of using the API method that checks for invalid pointers. This vulnerability affects Firefox < 86.