Through use of reportValidity() and window.open(), a plain-text validation message could have been overlaid on another origin, leading to possible user confusion and spoofing attacks. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.

Navigations were being allowed when dragging a URL from a cross-origin iframe into the same tab which could lead to website spoofing attacks. This vulnerability affects Firefox < 109, Thunderbird < 102.7, and Firefox ESR < 102.7.

Dragging a URL from a cross-origin iframe that was removed during the drag could have led to user confusion and website spoofing attacks. This vulnerability affects Firefox < 111, Firefox ESR < 102.9, and Thunderbird < 102.9.

An attacker could have abused XSLT error handling to associate attacker-controlled content with another origin which was displayed in the address bar. This could have been used to fool the user into submitting data intended for the spoofed origin. This vulnerability affects Thunderbird < 102.2, Thunderbird < 91.13, Firefox ESR < 91.13, Firefox ESR < 102.2, and Firefox < 104.

By encoding Unicode whitespace characters within the From email header, an attacker can spoof the sender email address that Thunderbird displays. This vulnerability affects Thunderbird < 68.8.0.

Remote Agent, used in WebDriver, did not validate the Host or Origin headers. This could have allowed websites to connect back locally to the user's browser to control it. <br>*This bug only affected Firefox when WebDriver was enabled, which is not the default configuration.*. This vulnerability affects Firefox < 97.

Long hostnames in URLs could be leveraged to obscure the actual host of the website or spoof the website address This vulnerability affects Firefox for iOS < 134.

A website could prevent a user from exiting full-screen mode via alert and prompt calls. This could lead to user confusion and possible spoofing attacks. This vulnerability affects Firefox < 115.

The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a connection to be transparently upgraded to TLS while retaining the visual properties of an HTTP connection, including being same-origin with unencrypted connections on port 80. However, if a second encrypted port on the same IP address (e.g. port 8443) did not opt-in to opportunistic encryption; a network attacker could forward a connection from the browser to port 443 to port 8443, causing the browser to treat the content of port 8443 as same-origin with HTTP. This was resolved by disabling the Opportunistic Encryption feature, which had low usage. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

On Windows 10, when using the 'Save As' functionality, an attacker could have tricked the browser into saving the file with a disallowed extension such as `.url` by including an invalid character in the extension. *Note:* This issue only affected Windows operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 127, Firefox ESR < 115.12, and Thunderbird < 115.12.

A "data:" URL loaded in a new tab did not inherit the Content Security Policy (CSP) of the original page, allowing for bypasses of the policy including the execution of JavaScript. In prior versions when "data:" documents also inherited the context of the original page this would allow for potential cross-site scripting (XSS) attacks. This vulnerability affects Firefox < 57.

The SELECT element implementation in Mozilla Firefox before 25.0, Firefox ESR 24.x before 24.1, Thunderbird before 24.1, and SeaMonkey before 2.22 does not properly restrict the nature or placement of HTML within a dropdown menu, which allows remote attackers to spoof the address bar or conduct clickjacking attacks via vectors that trigger navigation off of a page containing this element.

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.

Cross-site scripting (XSS) vulnerability in Mozilla Firefox before 26.0 and SeaMonkey before 2.23 makes it easier for remote attackers to inject arbitrary web script or HTML by leveraging a Same Origin Policy violation triggered by lack of a charset parameter in a Content-Type HTTP header.

Mozilla Firefox before 26.0 and SeaMonkey before 2.23 do not properly consider the sandbox attribute of an IFRAME element during processing of a contained OBJECT element, which allows remote attackers to bypass intended sandbox restrictions via a crafted web site.

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.

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.

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.

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.

Documents loaded with the CSP sandbox directive could have escaped the sandbox's script restriction by embedding additional content. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

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.

Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a stepping stone to further an attack with other vulnerabilities. This vulnerability affects Thunderbird < 91.4.0.

WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension. This vulnerability affects Firefox < 95.

When receiving a URL through a SEND intent, Firefox would have searched for the text, but subsequent usages of the address bar might have caused the URL to load unintentionally, which could lead to XSS and spoofing attacks. *This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 95.

It was possible to recreate previous cursor spoofing attacks against users with a zoomed native cursor. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

When receiving an OpenPGP/MIME signed email message that contains an additional outer MIME message layer, for example a message footer added by a mailing list gateway, Thunderbird only considered the inner signed message for the signature validity. This gave the false impression that the additional contents were also covered by the digital signature. Starting with Thunderbird version 91.4.1, only the signature that belongs to the top level MIME part will be considered for the displayed status. This vulnerability affects Thunderbird < 91.4.1.

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 21.0, Firefox ESR 17.x before 17.0.6, Thunderbird before 17.0.6, and Thunderbird ESR 17.x before 17.0.6 does not prevent acquisition of chrome privileges during calls to content level constructors, which allows remote attackers to bypass certain read-only restrictions and conduct cross-site scripting (XSS) attacks via a crafted web site.

Multiple cross-site scripting (XSS) vulnerabilities in editflagtypes.cgi in Bugzilla 2.x, 3.x, and 4.0.x before 4.0.11; 4.1.x and 4.2.x before 4.2.7; and 4.3.x and 4.4.x before 4.4.1 allow remote attackers to inject arbitrary web script or HTML via the (1) id or (2) sortkey parameter.

Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before 17.0.7 do not prevent the inclusion of body data in an XMLHttpRequest HEAD request, which makes it easier for remote attackers to conduct cross-site request forgery (CSRF) attacks via a crafted web site.

Mozilla Firefox before 1.5.0.7 and SeaMonkey before 1.0.5 allows remote attackers to bypass the security model and inject content into the sub-frame of another site via targetWindow.frames[n].document.open(), which facilitates spoofing and other attacks.

Mozilla Firefox before 23.0, Firefox ESR 17.x before 17.0.8, Thunderbird before 17.0.8, Thunderbird ESR 17.x before 17.0.8, and SeaMonkey before 2.20 use an incorrect URI within unspecified comparisons during enforcement of the Same Origin Policy, which allows remote attackers to conduct cross-site scripting (XSS) attacks or install arbitrary add-ons via a crafted web site.

Mozilla Firefox before 23.0, Firefox ESR 17.x before 17.0.8, Thunderbird before 17.0.8, Thunderbird ESR 17.x before 17.0.8, and SeaMonkey before 2.20 do not properly handle the interaction between FRAME elements and history, which allows remote attackers to conduct cross-site scripting (XSS) attacks via vectors involving spoofing a relative location in a previously visited document.

The getUserMedia permission implementation in Mozilla Firefox before 22.0 references the URL of a top-level document instead of the URL of a specific page, which makes it easier for remote attackers to trick users into permitting camera or microphone access via a crafted web site that uses IFRAME elements.

The Web Workers implementation in Mozilla Firefox before 23.0, Firefox ESR 17.x before 17.0.8, Thunderbird before 17.0.8, Thunderbird ESR 17.x before 17.0.8, and SeaMonkey before 2.20 does not properly restrict XMLHttpRequest calls, which allows remote attackers to bypass the Same Origin Policy and conduct cross-site scripting (XSS) attacks via unspecified vectors.

The XrayWrapper implementation in Mozilla Firefox before 23.0 and SeaMonkey before 2.20 does not properly address the possibility of an XBL scope bypass resulting from non-native arguments in XBL function calls, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks by leveraging access to an unprivileged object.

Cross-site scripting (XSS) vulnerability in show_bug.cgi in Bugzilla before 3.6.13, 3.7.x and 4.0.x before 4.0.10, 4.1.x and 4.2.x before 4.2.5, and 4.3.x and 4.4.x before 4.4rc2 allows remote attackers to inject arbitrary web script or HTML via the id parameter in conjunction with an invalid value of the format parameter.

When delegating navigations to the operating system, Firefox would accept the `mk` scheme which might allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. *This bug only affects Firefox for Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 92, Thunderbird < 91.1, Thunderbird < 78.14, Firefox ESR < 78.14, and Firefox ESR < 91.1.

Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

Mixed-content checks were unable to analyze opaque origins which led to some mixed content being loaded. This vulnerability affects Firefox < 92.

Mozilla Firefox 2.0 before 2.0.0.1 allows remote attackers to bypass Cross-Site Scripting (XSS) protection via vectors related to a Function.prototype regression error.

Mozilla Firefox and Thunderbird before 1.5.0.4 strip the Unicode Byte-order-Mark (BOM) from a UTF-8 page before the page is passed to the parser, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a BOM sequence in the middle of a dangerous tag such as SCRIPT.

Bugzilla 2.20rc1 through 2.20 and 2.21.1, when using RSS 1.0, allows remote attackers to conduct cross-site scripting (XSS) attacks via a title element with HTML encoded sequences such as "&gt;", which are automatically decoded by some RSS readers. NOTE: this issue is not in Bugzilla itself, but rather due to design or documentation inconsistencies within RSS, or implementation vulnerabilities in RSS readers. While this issue normally would not be included in CVE, it is being identified since the Bugzilla developers have addressed it.

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 evalInSandbox implementation in Mozilla Firefox before 17.0, Firefox ESR 10.x before 10.0.11, Thunderbird before 17.0, Thunderbird ESR 10.x before 10.0.11, and SeaMonkey before 2.14 uses an incorrect context during the handling of JavaScript code that sets the location.href property, which allows remote attackers to conduct cross-site scripting (XSS) attacks or read arbitrary files by leveraging a sandboxed add-on.

The nsLocation::CheckURL function in Mozilla Firefox before 16.0.2, Firefox ESR 10.x before 10.0.10, Thunderbird before 16.0.2, Thunderbird ESR 10.x before 10.0.10, and SeaMonkey before 2.13.2 does not properly determine the calling document and principal in its return value, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted web site, and makes it easier for remote attackers to execute arbitrary JavaScript code by leveraging certain add-on behavior.

The HZ-GB-2312 character-set implementation in Mozilla Firefox before 17.0, Firefox ESR 10.x before 10.0.11, Thunderbird before 17.0, Thunderbird ESR 10.x before 10.0.11, and SeaMonkey before 2.14 does not properly handle a ~ (tilde) character in proximity to a chunk delimiter, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a crafted document.

Mozilla Firefox and Thunderbird 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 returns the Object class prototype instead of the global window object when (1) .valueOf.call or (2) .valueOf.apply are called without any arguments, which allows remote attackers to conduct cross-site scripting (XSS) attacks.

Mozilla Firefox 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 allows remote attackers to inject arbitrary Javascript into other sites by (1) "using a modal alert to suspend an event handler while a new page is being loaded", (2) using eval(), and using certain variants involving (3) "new Script;" and (4) using window.__proto__ to extend eval, aka "cross-site JavaScript injection".