Mozilla Firefox before 2.0.0.17 and 3.x before 3.0.2, Thunderbird before 2.0.0.17, and SeaMonkey before 1.1.12 allow remote attackers to bypass cross-site scripting (XSS) protection mechanisms and conduct XSS attacks via byte order mark (BOM) characters that are removed from JavaScript code before execution, aka "Stripped BOM characters bug."

Add-on updates failed to verify that the add-on ID inside the signed package matched the ID of the add-on being updated. An attacker who could perform a man-in-the-middle attack on the user's connection to the update server and defeat the certificate pinning protection could provide a malicious signed add-on instead of a valid update. This vulnerability affects Firefox ESR < 45.5 and Firefox < 50.

An issue where a "<select>" dropdown menu can be used to cover location bar content, resulting in potential spoofing attacks. This attack requires e10s to be enabled in order to function. This vulnerability affects Firefox < 50.

Mozilla Firefox 2.0.0.14, and other versions before 2.0.0.17, allows remote attackers to bypass cross-site scripting (XSS) protection mechanisms and conduct XSS attacks via HTML-escaped low surrogate characters that are ignored by the HTML parser, as demonstrated by a "jav&#56325ascript" sequence, aka "HTML escaped low surrogates bug."

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.

Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 process JavaScript event-handler attributes of a MARQUEE element within a sandboxed IFRAME element that lacks the sandbox="allow-scripts" attribute value, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted web site.

Mozilla Firefox before 48.0 on Android allows remote attackers to spoof the address bar via left-to-right characters in conjunction with a right-to-left character set.

A mechanism where disruption of the loading of a new web page can cause the previous page's favicon and SSL indicator to not be reset when the new page is loaded. Note: this issue only affects Firefox for Android. Desktop Firefox is unaffected. This vulnerability affects Firefox < 50.

Mozilla Firefox before 48.0 does not properly set the LINKABLE and URI_SAFE_FOR_UNTRUSTED_CONTENT flags of about: URLs that are used for error pages, which makes it easier for remote attackers to conduct spoofing attacks via a crafted URL, as demonstrated by misleading text after an about:neterror?d= substring.

Mozilla Firefox before 48.0 allows remote attackers to spoof the location bar via crafted characters in the media type of a data: URL.

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.

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.

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."

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.

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.

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.

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.

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

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 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.

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.

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."

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

Mozilla Firefox before 41.0 on Android allows user-assisted remote attackers to spoof address-bar attributes by leveraging lack of navigation after a paste of a URL with a nonstandard scheme, as demonstrated by spoofing an SSL attribute.

The Reader View implementation in Mozilla Firefox before 42.0 has an improper whitelist, which makes it easier for remote attackers to bypass the Content Security Policy (CSP) protection mechanism and conduct cross-site scripting (XSS) attacks via vectors involving SVG animations and the about:reader URL.

Mozilla Firefox before 39.0, Firefox ESR 38.x before 38.1, and Thunderbird before 38.1 do not enforce key pinning upon encountering an X.509 certificate problem that generates a user dialog, which allows user-assisted man-in-the-middle attackers to bypass intended access restrictions by triggering a (1) expired certificate or (2) mismatched hostname for a domain with pinning enabled.

Mozilla Firefox before 2.0.0.12 and SeaMonkey before 1.1.8 allows user-assisted remote attackers to trick the user into uploading arbitrary files via label tags that shift focus to a file input field, aka "focus spoofing."

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.

js/src/proxy/Proxy.cpp in Mozilla Firefox before 41.0 mishandles certain receiver arguments, which allows remote attackers to bypass intended window access restrictions via a crafted web site.

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.

The nsCSPHostSrc::permits function in dom/security/nsCSPUtils.cpp in Mozilla Firefox before 40.0 does not implement the Content Security Policy Level 2 exceptions for the blob, data, and filesystem URL schemes during wildcard source-expression matching, which might make it easier for remote attackers to conduct cross-site scripting (XSS) attacks by leveraging unexpected policy-enforcement behavior.