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.

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.

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.

Links in a sandboxed iframe could open an external app on Android without the required "allow-" permission. This vulnerability was fixed in Firefox 144 and Thunderbird 144.

There was a way to change the value of JavaScript Object properties that were supposed to be non-writeable. This vulnerability was fixed in Firefox 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.

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.

A compromised content process could have performed session history manipulations it should not have been able to due to testing infrastructure that was not restricted to testing-only configurations. This vulnerability affects Firefox < 88.

Thunderbird did not check if the user ID associated with an OpenPGP key has a valid self signature. An attacker may create a crafted version of an OpenPGP key, by either replacing the original user ID, or by adding another user ID. If Thunderbird imports and accepts the crafted key, the Thunderbird user may falsely conclude that the false user ID belongs to the correspondent. This vulnerability affects Thunderbird < 78.9.1.

An XSS bug in internal error pages could have led to various spoofing attacks, including other error pages and the address bar. Note: This issue only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 85.

Through complicated navigations with new windows, an HTTP page could have inherited a secure lock icon from an HTTPS page. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

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.

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.

When sharing geolocation during an active WebRTC share, Firefox could have reset the webRTC sharing state in the user interface, leading to loss of control over the currently granted permission. This vulnerability affects Firefox < 85.

A malicious extension could have opened a popup window lacking an address bar. The title of the popup lacking an address bar should not be fully controllable, but in this situation was. This could have been used to spoof a website and attempt to trick the user into providing credentials. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

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.

The DOMParser API did not properly process '<noscript>' elements for escaping. This could be used as an mXSS vector to bypass an HTML Sanitizer. This vulnerability affects Firefox < 86.

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.

The TLS protocol 1.2 and earlier, when a DHE_EXPORT ciphersuite is enabled on a server but not on a client, does not properly convey a DHE_EXPORT choice, which allows man-in-the-middle attackers to conduct cipher-downgrade attacks by rewriting a ClientHello with DHE replaced by DHE_EXPORT and then rewriting a ServerHello with DHE_EXPORT replaced by DHE, aka the "Logjam" issue.

Mozilla Firefox before 40.0 allows man-in-the-middle attackers to bypass a mixed-content protection mechanism via a feed: URL in a POST request.

Spoofing issue in the Privacy: Anti-Tracking component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.

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.

Cross-site scripting (XSS) vulnerability in the Search app in Gaia in Mozilla Firefox OS before 2.2 allows remote attackers to inject arbitrary HTML via a crafted search link that is mishandled after re-opening the browser or opening the tab view.

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.

Opening links via the contextual menu in Focus iOS for certain URL schemes would fail to load but would not refresh the toolbar correctly, allowing attackers to spoof websites if users were coerced into opening a link explicitly through a long-press. This vulnerability was fixed in Focus for iOS 143.0.

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 Network Security Services (NSS) before 3.19.1, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, and other products, does not properly perform Elliptical Curve Cryptography (ECC) multiplications, which makes it easier for remote attackers to spoof ECDSA signatures via unspecified vectors.

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.

Mozilla Firefox 2.0.0.5, Thunderbird 2.0.0.5 and before 1.5.0.13, and SeaMonkey 1.1.3 allows remote attackers to conduct cross-site scripting (XSS) attacks with chrome privileges via an addon that inserts a (1) javascript: or (2) data: link into an about:blank document loaded by chrome via (a) the window.open function or (b) a content.location assignment, aka "Cross Context Scripting." NOTE: this issue is caused by a CVE-2007-3089 regression.

Cross-site scripting (XSS) vulnerability in enter_bug.cgi in Bugzilla 2.17.1 through 2.20.4, 2.22.x before 2.22.3, and 3.x before 3.0.1 allows remote attackers to inject arbitrary web script or HTML via the buildid field in the "guided form."

Same-origin policy bypass in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 148.0.2.

Navigations through the Android-specific `intent` URL scheme could have been misused to escape iframe sandbox. Note: This issue only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 85.

Spoofing issue in Thunderbird. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.

Cross-site scripting (XSS) vulnerability in Mozilla Firefox before 2.0.0.5 allows remote attackers to inject arbitrary web script "into another site's context" via a "timing issue" involving the (1) addEventListener or (2) setTimeout function, probably by setting events that activate after the context has changed.

The UITour::onPageEvent function in Mozilla Firefox before 36.0 does not ensure that an API call originates from a foreground tab, which allows remote attackers to conduct spoofing and clickjacking attacks by leveraging access to a UI Tour web site.

Mozilla Firefox before 37.0 does not require an HTTPS session for lightweight theme add-on installations, which allows man-in-the-middle attackers to bypass an intended user-confirmation requirement by deploying a crafted web site and conducting a DNS spoofing attack against a mozilla.org subdomain.

The HTTP Alternative Services feature in Mozilla Firefox before 37.0.1 allows man-in-the-middle attackers to bypass an intended X.509 certificate-verification step for an SSL server by specifying that server in the uri-host field of an Alt-Svc HTTP/2 response header.

Mozilla Firefox before 37.0 on OS X does not ensure that the cursor is visible, which allows remote attackers to conduct clickjacking attacks via a Flash object in conjunction with DIV elements associated with layered presentation, and crafted JavaScript code that interacts with an IMG element.

Through a series of API calls and redirects, an attacker-controlled alert dialog could have been displayed on another website (with the victim website's URL shown). This vulnerability affects Firefox < 123, Firefox ESR < 115.8, and Thunderbird < 115.8.

Mitigation bypass in the Privacy: Anti-Tracking component. This vulnerability was fixed in Firefox 147.0.2.

Missing thread synchronization primitives could have led to a data race on members of the PlaybackParams structure. This vulnerability affects Firefox < 133 and Thunderbird < 133.

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.

Spoofing issue in the Address Bar component of Firefox Focus for Android. This vulnerability was fixed in Firefox 142.

Spoofing issue in the Address Bar component. This vulnerability was fixed in Firefox 142 and Firefox ESR 140.2.