Crafted CSS in an RSS feed can leak and reveal local path strings, which may contain user name. This vulnerability affects Thunderbird < 52.5.2.

A combination of an external SVG image referenced on a page and the coloring of anchor links stored within this image can be used to determine which pages a user has in their history. This can allow a malicious website to query user history. Note: This issue only affects Firefox 57. Earlier releases are not affected. This vulnerability affects Firefox < 57.0.1.

Using SVG filters that don't use the fixed point math implementation on a target iframe, a malicious page can extract pixel values from a targeted user. This can be used to extract history information and read text values across domains. This violates same-origin policy and leads to information disclosure. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

Proxy Auto-Config (PAC) files can specify a JavaScript function called for all URL requests with the full URL path which exposes more information than would be sent to the proxy itself in the case of HTTPS. Normally the Proxy Auto-Config file is specified by the user or machine owner and presumed to be non-malicious, but if a user has enabled Web Proxy Auto Detect (WPAD) this file can be served remotely. This vulnerability affects Firefox < 51.

The S/MIME specification allows a Cipher Block Chaining (CBC) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL.

The OpenPGP specification allows a Cipher Feedback Mode (CFB) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL. NOTE: third parties report that this is a problem in applications that mishandle the Modification Detection Code (MDC) feature or accept an obsolete packet type, not a problem in the OpenPGP specification

OpenPGP secret keys that were imported using Thunderbird version 78.8.1 up to version 78.10.1 were stored unencrypted on the user's local disk. The master password protection was inactive for those keys. Version 78.10.2 will restore the protection mechanism for newly imported keys, and will automatically protect keys that had been imported using affected Thunderbird versions. This vulnerability affects Thunderbird < 78.10.2.

When a download was initiated, the client did not check whether it was in normal or private browsing mode, which led to private mode cookies being shared in normal browsing mode. This vulnerability affects Firefox for iOS < 34.

After requesting multiple permissions, and closing the first permission panel, subsequent permission panels will be displayed in a different position but still record a click in the default location, making it possible to trick a user into accepting a permission they did not want to. *This bug only affects Firefox on Linux. Other operating systems are unaffected.*. This vulnerability affects Firefox < 91 and Thunderbird < 91.

Due to incorrect JIT optimization, we incorrectly interpreted data from the wrong type of object, resulting in the potential leak of a single bit of memory. This vulnerability affects Firefox < 91 and Thunderbird < 91.

Firefox used to cache the last filename used for printing a file. When generating a filename for printing, Firefox usually suggests the web page title. The caching and suggestion techniques combined may have lead to the title of a website visited during private browsing mode being stored on disk. This vulnerability affects Firefox < 89.

The SSL protocol, as used in certain configurations in Microsoft Windows and Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, Opera, and other products, encrypts data by using CBC mode with chained initialization vectors, which allows man-in-the-middle attackers to obtain plaintext HTTP headers via a blockwise chosen-boundary attack (BCBA) on an HTTPS session, in conjunction with JavaScript code that uses (1) the HTML5 WebSocket API, (2) the Java URLConnection API, or (3) the Silverlight WebClient API, aka a "BEAST" attack.

The browser could have been confused into transferring a screen sharing state into another tab, which would leak unintended information. This vulnerability affects Firefox < 85.

If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

When processing a redirect with a conflicting Referrer-Policy, Firefox would have adopted the redirect's Referrer-Policy. This would have potentially resulted in more information than intended by the original origin being provided to the destination of the redirect. This vulnerability affects Firefox < 86.

As specified in the W3C Content Security Policy draft, when creating a violation report, "User agents need to ensure that the source file is the URL requested by the page, pre-redirects. If that’s not possible, user agents need to strip the URL down to an origin to avoid unintentional leakage." Under certain types of redirects, Firefox incorrectly set the source file to be the destination of the redirects. This was fixed to be the redirect destination's origin. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

It was found that Diffie Hellman Client key exchange handling in NSS 3.21.x was vulnerable to small subgroup confinement attack. An attacker could use this flaw to recover private keys by confining the client DH key to small subgroup of the desired group.

Mozilla Firefox before 3.5.19 and 3.6.x before 3.6.17, and SeaMonkey before 2.0.14, does not properly implement autocompletion for forms, which allows remote attackers to read form history entries via a Java applet that spoofs interaction with the autocomplete controls.

Mozilla Firefox before 3.5.19 and 3.6.x before 3.6.17, and SeaMonkey before 2.0.14, does not properly use nsTreeRange data structures, which allows remote attackers to execute arbitrary code via unspecified vectors that lead to a "dangling pointer."

The X.509 certificate validation functionality in Mozilla Firefox 4.0.x through 4.0.1 does not properly implement single-session security exceptions, which might make it easier for user-assisted remote attackers to spoof an SSL server via an untrusted certificate that triggers potentially unwanted local caching of documents from that server.

Mozilla Firefox before 3.5.16 and 3.6.x before 3.6.13, Thunderbird before 3.0.11 and 3.1.x before 3.1.7, and SeaMonkey before 2.0.11 do not properly validate downloadable fonts before use within an operating system's font implementation, which allows remote attackers to execute arbitrary code via vectors related to @font-face Cascading Style Sheets (CSS) rules.

The NS_SecurityCompareURIs function in netwerk/base/public/nsNetUtil.h in Mozilla Firefox before 3.5.16 and 3.6.x before 3.6.13, and SeaMonkey before 2.0.11, does not properly handle (1) about:neterror and (2) about:certerror pages, which allows remote attackers to spoof the location bar via a crafted web site.

Visual truncation vulnerability in netwerk/dns/src/nsIDNService.cpp in Mozilla Firefox before 3.0.11 and SeaMonkey before 1.1.17 allows remote attackers to spoof the location bar via an IDN with invalid Unicode characters that are displayed as whitespace, as demonstrated by the \u115A through \u115E characters.

intl/uconv/util/nsUnicodeDecodeHelper.cpp in Mozilla Firefox before 3.6.7 and Thunderbird before 3.1.1 inserts a U+FFFD sequence into text in certain circumstances involving undefined positions, which might make it easier for remote attackers to conduct cross-site scripting (XSS) attacks via crafted 8-bit text.

The nsIScriptableUnescapeHTML.parseFragment method in the ParanoidFragmentSink protection mechanism in Mozilla Firefox before 3.5.17 and 3.6.x before 3.6.14, Thunderbird before 3.1.8, and SeaMonkey before 2.0.12 does not properly sanitize HTML in a chrome document, which makes it easier for remote attackers to execute arbitrary JavaScript with chrome privileges via a javascript: URI in input to an extension, as demonstrated by a javascript:alert sequence in (1) the HREF attribute of an A element or (2) the ACTION attribute of a FORM element.

The XMLDocument::load function in Mozilla Firefox before 3.5.9 and 3.6.x before 3.6.2, Thunderbird before 3.0.4, and SeaMonkey before 2.0.4 does not perform the expected nsIContentPolicy checks during loading of content by XML documents, which allows attackers to bypass intended access restrictions via crafted content.

Mozilla Firefox before 3.5.9 and 3.6.x before 3.6.2, and SeaMonkey before 2.0.4, executes a mail application in situations where an IMG element has a SRC attribute that is a redirect to a mailto: URL, which allows remote attackers to cause a denial of service (excessive application launches) via an HTML document with many images.

Sage 1.4.3 and earlier extension for Firefox performs certain operations with chrome privileges, which allows remote attackers to execute arbitrary commands and perform cross-domain scripting attacks via the description tag of an RSS feed.

Yoono extension before 6.1.1 for Firefox performs certain operations with chrome privileges, which allows user-assisted remote attackers to execute arbitrary commands and perform cross-domain scripting attacks via DOM event handlers such as onload.

infoRSS 1.1.4.2 and earlier extension for Firefox performs certain operations with chrome privileges, which allows remote attackers to execute arbitrary commands and perform cross-domain scripting attacks via the description tag of an RSS feed.

Visual truncation vulnerability in Mozilla Firefox before 3.0.14, and 3.5.x before 3.5.3, allows remote attackers to trigger a vertical scroll and spoof URLs via unspecified Unicode characters with a tall line-height property.

Mozilla Firefox before 3.0.13, and 3.5.x before 3.5.2, allows remote attackers to spoof the address bar, and possibly conduct phishing attacks, via a crafted web page that calls window.open with an invalid character in the URL, makes document.write calls to the resulting object, and then calls the stop method during the loading of the error page.

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.

On pages containing an iframe, the "data:" protocol can be used to create a modal alert that will render over arbitrary domains following page navigation, spoofing of the origin of the modal alert from the iframe content. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

Mozilla Firefox before 3.0.12, and 3.5.x before 3.5.2, allows remote SOCKS5 proxy servers to cause a denial of service (data stream corruption) via a long domain name in a reply.

nsViewManager.cpp in Mozilla Firefox 3.0.2 through 3.0.10 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via vectors related to interaction with TinyMCE.

Mozilla Firefox 3.0.10 and earlier on Linux allows remote attackers to cause a denial of service (application crash) via a URI for a large GIF image in the BACKGROUND attribute of a BODY element.

Mozilla Firefox before 3.0.7, Thunderbird before 2.0.0.21, and SeaMonkey before 1.1.15 decode invisible characters when they are displayed in the location bar, which causes an incorrect address to be displayed and makes it easier for remote attackers to spoof URLs and conduct phishing attacks.

The view-source: URI implementation in Mozilla Firefox before 3.0.9, Thunderbird, and SeaMonkey does not properly implement the Same Origin Policy, which allows remote attackers to (1) bypass crossdomain.xml restrictions and connect to arbitrary web sites via a Flash file; (2) read, create, or modify Local Shared Objects via a Flash file; or (3) bypass unspecified restrictions and render content via vectors involving a jar: URI.

Mozilla Firefox 3.0.8 and earlier 3.0.x versions allows remote attackers to cause a denial of service (memory corruption) via an XML document composed of a long series of start-tags with no corresponding end-tags. NOTE: it was later reported that 3.0.10 and earlier are also affected.

Firefox 3.x before 3.0.4, Firefox 2.x before 2.0.0.18, and SeaMonkey 1.x before 1.1.13 allows remote attackers to bypass the protection mechanism for codebase principals and execute arbitrary script via the -moz-binding CSS property in a signed JAR file.

Mozilla Firefox 3.0.5 on Windows Vista allows remote attackers to cause a denial of service (application crash) via JavaScript code with a long string value for the hash property (aka location.hash). NOTE: it was later reported that earlier versions are also affected, and that the impact is CPU consumption and application hang in unspecified circumstances perhaps involving other platforms.

jslock.cpp in Mozilla Firefox 3.x before 3.0.2, Firefox 2.x before 2.0.0.18, Thunderbird 2.x before 2.0.0.18, and SeaMonkey 1.x before 1.1.13 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code by modifying the window.__proto__.__proto__ object in a way that causes a lock on a non-native object, which triggers an assertion failure related to the OBJ_IS_NATIVE function.