After a website had entered fullscreen mode, it could have used a previously opened popup to obscure the notification that indicates the browser is in fullscreen mode. Combined with spoofing the browser chrome, this could have led to confusing the user about the current origin of the page and credential theft or other attacks. This vulnerability affects Firefox < 74.

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

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.

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.

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.

When a user downloaded a file in Firefox for Android, if a cookie is set, it would have been re-sent during a subsequent file download operation on the same domain, regardless of whether the original and subsequent request were in private and non-private browsing modes. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 83.

Nunjucks is a full featured templating engine for JavaScript. Versions 2.4.2 and lower have a cross site scripting (XSS) vulnerability in autoescape mode. In autoescape mode, all template vars should automatically be escaped. By using an array for the keys, such as `name[]=<script>alert(1)</script>`, it is possible to bypass autoescaping and inject content into the DOM.

Mozilla Firefox before 2.0.0.15 and SeaMonkey before 1.1.10 allow remote attackers to bypass the Same Origin Policy and conduct cross-site scripting (XSS) attacks via vectors involving (1) an event handler attached to an outer window, (2) a SCRIPT element in an unloaded document, or (3) the onreadystatechange handler in conjunction with an XMLHttpRequest.

Cross-site scripting (XSS) vulnerability in Bugzilla 2.17.2 and later allows remote attackers to inject arbitrary web script or HTML via the id parameter to the "Format for Printing" view or "Long Format" bug list.

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.

When a new protocol handler is registered, the API accepts a title argument which can be used to mislead users about which domain is registering the new protocol. This may result in the user approving a protocol handler that they otherwise would not have. This vulnerability affects Firefox < 63.

Mozilla Firefox before 2.0.0.15 and SeaMonkey before 1.1.10 do not properly escape HTML in file:// URLs in directory listings, which allows remote attackers to conduct cross-site scripting (XSS) attacks or have unspecified other impact via a crafted filename.

Mozilla Network Security Services (NSS) before 3.19, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, Thunderbird before 38.1, and other products, does not properly determine state transitions for the TLS state machine, which allows man-in-the-middle attackers to defeat cryptographic protection mechanisms by blocking messages, as demonstrated by removing a forward-secrecy property by blocking a ServerKeyExchange message, aka a "SMACK SKIP-TLS" issue.

GUI overlay vulnerability in Mozilla Firefox before 2.0.0.13 and SeaMonkey before 1.1.9 allows remote attackers to spoof form elements and redirect user inputs via a borderless XUL pop-up window from a background tab.

Cross-site scripting (XSS) vulnerability in Mozilla Firefox before 1.5.0.4 allows user-assisted remote attackers to inject arbitrary web script or HTML by tricking a user into (1) performing a "View Image" on a broken image in which the SRC attribute contains a Javascript URL, or (2) selecting "Show only this frame" on a frame whose SRC attribute contains a Javascript URL.

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 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.

A reflected XSS vulnerability exists within the gateway, allowing an attacker to craft a specialized URL which could steal the user's authentication token. When combined with CVE-2020-6803, an attacker could fully compromise the system.

When following a link that opened an intent://-schemed URL, causing a custom tab to be opened, Firefox for Android could be tricked into displaying the incorrect URI. <br> *Note: This issue only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox ESR < 68.7.

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.

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)."

If a template tag was used in a select tag, the parser could be confused and allow JavaScript parsing and execution when it should not be allowed. A site that relied on the browser behaving correctly could suffer a cross-site scripting vulnerability as a result. In general, this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled when reading mail, but is potentially a risk in browser or browser-like contexts. This vulnerability affects Thunderbird < 68.5, Firefox < 73, and Firefox < ESR68.5.

In Mozilla Bleach before 3.12, a mutation XSS in bleach.clean when RCDATA and either svg or math tags are whitelisted and the keyword argument strip=False.

Cross-site scripting (XSS) vulnerability in Mozilla Firefox before 2.0.0.13, Thunderbird before 2.0.0.13, and SeaMonkey before 1.1.9 allows remote attackers to inject arbitrary web script or HTML via event handlers, aka "Universal XSS using event handlers."

Multiple cross-site scripting (XSS) vulnerabilities in Mozilla Firefox before 2.0.0.12, Thunderbird before 2.0.0.12, and SeaMonkey before 1.1.8 allow remote attackers to inject arbitrary web script or HTML via certain character encodings, including (1) a backspace character that is treated as whitespace, (2) 0x80 with Shift_JIS encoding, and (3) "zero-length non-ASCII sequences" in certain Asian character sets.

Mozilla Firefox before 2.0.0.12, Thunderbird before 2.0.0.12, and SeaMonkey before 1.1.8 allows remote attackers to execute script outside of the sandbox and conduct cross-site scripting (XSS) attacks via multiple vectors including the XMLDocument.load function, aka "JavaScript privilege escalation bugs."

Cross-site scripting (XSS) vulnerability in Bugzilla before 2.18, including 2.16.x before 2.16.11, allows remote attackers to inject arbitrary HTML and web script via forced error messages, as demonstrated using the action parameter.

CRLF injection vulnerability in Mozilla Firefox before 2.0.0.12 allows remote user-assisted web sites to corrupt the user's password store via newlines that are not properly handled when the user saves a password.

The jar protocol handler in Mozilla Firefox before 2.0.0.10 and SeaMonkey before 1.1.7 does not update the origin domain when retrieving the inner URL parameter yields an HTTP redirect, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a jar: URI, a different vulnerability than CVE-2007-5947.

In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

When a malicious application installed on the user's device broadcast an Intent to Firefox for Android, arbitrary headers could have been specified, leading to attacks such as abusing ambient authority or session fixation. This was resolved by only allowing certain safe-listed headers. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 84.

Cross-origin iframes that contained a login form could have been recognized by the login autofill service, and populated. This could have been used in clickjacking attacks, as well as be read across partitions in dynamic first party isolation. This vulnerability affects Firefox < 83.

Mozilla Firefox before 2.0.0.10 and SeaMonkey before 1.1.7 sets the Referer header to the window or frame in which script is running, instead of the address of the content that initiated the script, which allows remote attackers to spoof HTTP Referer headers and bypass Referer-based CSRF protection schemes by setting window.location and using a modal alert dialog that causes the wrong Referer to be sent.

It was possible to cause the browser to enter fullscreen mode without displaying the security UI; thus making it possible to attempt a phishing attack or otherwise confuse the user. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

OneCRL was non-functional in the new Firefox for Android due to a missing service initialization. This could result in a failure to enforce some certificate revocations. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 83.

When a HTTPS pages was embedded in a HTTP page, and there was a service worker registered for the former, the service worker could have intercepted the request for the secure page despite the iframe not being a secure context due to the (insecure) framing. This vulnerability affects Firefox < 84.

When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 83.

A flaw in Mozilla's embedded certificate code might allow web sites to install root certificates on devices without user approval.

When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses as these do not make sense coming from a DoH resolver. However when an IPv4 address was mapped through IPv6, these addresses were erroneously let through, leading to a potential DNS Rebinding attack. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization. An attacker already capable of exploiting an XSS vulnerability in privileged internal pages could have used this attack to bypass our built-in sanitizer. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

The jar protocol handler in Mozilla Firefox before 2.0.0.10 and SeaMonkey before 1.1.7 retrieves the inner URL regardless of its MIME type, and considers HTML documents within a jar archive to have the same origin as the inner URL, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a jar: URI.

When listening for page changes with a Mutation Observer, a malicious web page could confuse Firefox Screenshots into interacting with elements other than those that it injected into the page. This would lead to internal errors and unexpected behavior in the Screenshots code. This vulnerability affects Firefox < 83.

By attempting to connect a website using an unresponsive port, an attacker could have controlled the content of a tab while the URL bar displayed the original domain. *Note: This issue only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 84.

Cross-site scripting (XSS) vulnerability in Mozilla Firefox 2.0, when UTF-7 document content is rendered directly in UTF-7, allows remote attackers to inject arbitrary web script or HTML via a gopher URI that uses '/' (slash) characters to delimit a literal string within an XSS sequence, a related issue to CVE-2007-5414.

Cross-site scripting (XSS) vulnerability in the sidebar HTML page in the MouseoverDictionary before 0.6.2 extension for Mozilla Firefox allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

Mozilla Firefox before 2.0.0.8 and SeaMonkey before 1.1.5 can hide the window's titlebar when displaying XUL markup language documents, which makes it easier for remote attackers to conduct phishing and spoofing attacks by setting the hidechrome attribute.

Firefox did not block execution of scripts with incorrect MIME types when the response was intercepted and cached through a ServiceWorker. This could lead to a cross-site script inclusion vulnerability, or a Content Security Policy bypass. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.