Mozilla Necko, as used in Thunderbird 3.0.1, SeaMonkey, and other applications, performs DNS prefetching even when the app type is APP_TYPE_MAIL or APP_TYPE_EDITOR, which makes it easier for remote attackers to determine the network location of the application's user by logging DNS requests, as demonstrated by DNS requests triggered by reading text/plain e-mail messages in Thunderbird.

Template.pm in Bugzilla 3.3.2 through 3.4.3 and 3.5 through 3.5.1 allows remote attackers to discover the alias of a private bug by reading the (1) Depends On or (2) Blocks field of a related bug.

Mozilla Firefox 3.0.x before 3.0.18 and 3.5.x before 3.5.8, and SeaMonkey before 2.0.3, does not properly restrict read access to object properties in showModalDialog, which allows remote attackers to bypass the Same Origin Policy and conduct cross-site scripting (XSS) attacks via crafted dialogArguments values.

Mozilla 0.9.6 and earlier and Netscape 6.2 and earlier allows remote attackers to steal cookies from another domain via a link with a hex-encoded null character (%00) followed by the target domain.

Mozilla 1.0 allows remote attackers to steal cookies from other domains via a javascript: URL with a leading "//" and ending in a newline, which causes the host/path check to fail.

Bugzilla 2.14 before 2.14.2, and 2.16 before 2.16rc2, allows remote attackers to display restricted products and components via a direct HTTP request to queryhelp.cgi.

show_bug.cgi in Bugzilla before 2.14.1 allows a user with "Bugs Access" privileges to see other products that are not accessible to the user, by submitting a bug and reading the resulting Product pulldown menu.

When Private Browsing mode is used, it is possible for a web worker to write persistent data to IndexedDB and fingerprint a user uniquely. IndexedDB should not be available in Private Browsing mode and this stored data will persist across multiple private browsing mode sessions because it is not cleared when exiting. This vulnerability affects Firefox ESR < 52.5.2 and Firefox < 57.0.1.

A content security policy (CSP) "frame-ancestors" directive containing origins with paths allows for comparisons against those paths instead of the origin. This results in a cross-origin information leak of this path information. This vulnerability affects Firefox < 55.

The AES-GCM implementation in WebCrypto API accepts 0-length IV when it should require a length of 1 according to the NIST Special Publication 800-38D specification. This might allow for the authentication key to be determined in some instances. This vulnerability affects Firefox < 56.

If web content on a page is dragged onto portions of the browser UI, such as the tab bar, links can be opened that otherwise would not be allowed to open. This can allow malicious web content to open a locally stored file through "file:" URLs. This vulnerability affects Firefox < 56.

On Windows systems, if non-null-terminated strings are copied into the crash reporter for some specific registry keys, stack memory data can be copied until a null is found. This can potentially contain private data from the local system. Note: This attack only affects Windows operating systems. Other operating systems are not affected. This vulnerability affects Firefox < 55.

Same-origin policy protections can be bypassed on pages with embedded iframes during page reloads, allowing the iframes to access content on the top level page, leading to information disclosure. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

A vulnerability where the security wrapper does not deny access to some exposed properties using the deprecated "_exposedProps_" mechanism on proxy objects. These properties should be explicitly unavailable to proxy objects. This vulnerability affects Firefox < 57.

Response header name interning does not have same-origin protections and these headers are stored in a global registry. This allows stored header names to be available cross-origin. This vulnerability affects Firefox < 55.

Android intent URLs given to Firefox for Android can be used to navigate from HTTP or HTTPS URLs to local "file:" URLs, allowing for the reading of local data through a violation of same-origin policy. Note: This attack only affects Firefox for Android. Other operating systems are not affected. This vulnerability affects Firefox < 54.

If a document's Referrer Policy attribute is set to "no-referrer" sometimes two network requests are made for "<link>" elements instead of one. One of these requests includes the referrer instead of respecting the set policy to not include a referrer on requests. This vulnerability affects Firefox < 57.

An out-of-bounds read in WebGL with a maliciously crafted "ImageInfo" object during WebGL operations. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.

WebExtensions could use popups and panels in the extension UI to load an "about:" privileged URL, violating security checks that disallow this behavior. This vulnerability affects Firefox < 56.

Search.pm in Bugzilla 2.19.1 through 3.2.7, 3.3.1 through 3.4.7, 3.5.1 through 3.6.1, and 3.7 through 3.7.2 allows remote attackers to determine the group memberships of arbitrary users via vectors involving the Search interface, boolean charts, and group-based pronouns.

Mozilla does not prevent cookies that are sent over an insecure channel (HTTP) from also being sent over a secure channel (HTTPS/SSL) in the same domain, which could allow remote attackers to steal cookies and conduct unauthorized activities, aka "Cross Security Boundary Cookie Injection."

Data sent with in multipart channels, such as the multipart/x-mixed-replace MIME type, will ignore the referrer-policy response header, leading to potential information disclosure for sites using this header. This vulnerability affects Firefox < 51.

A mechanism to bypass file system access protections in the sandbox to use the file picker to access different files than those selected in the file picker through the use of relative paths. This allows for read only access to the local file system. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 52.1, and Firefox < 53.

The Gecko Media Plugin sandbox allows access to local files that match specific regular expressions. On OS OX, this matching allows access to some data in subdirectories of "/private/var" that could expose personal or temporary data. This has been updated to not allow access to "/private/var" and its subdirectories. Note: this issue only affects OS X. Other operating systems are not affected. This vulnerability affects Firefox < 52 and Thunderbird < 52.

Certain response codes in FTP connections can result in the use of uninitialized values for ports in FTP operations. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

A buffer overflow vulnerability while parsing "application/http-index-format" format content when the header contains improperly formatted data. This allows for an out-of-bounds read of data from memory. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

Feed preview for RSS feeds can be used to capture errors and exceptions generated by privileged content, allowing for the exposure of internal information not meant to be seen by web content. This vulnerability affects Firefox < 51.

A vulnerability while parsing "application/http-index-format" format content where uninitialized values are used to create an array. This could allow the reading of uninitialized memory into the arrays affected. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

If a crafted hyperlink is dragged and dropped to the bookmark bar or sidebar and the resulting bookmark is subsequently dragged and dropped into the web content area, an arbitrary query of a user's browser history can be run and transmitted to the content page via drop event data. This allows for the theft of browser history by a malicious site. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.

Mozilla Firefox before 3.0.15, and 3.5.x before 3.5.4, allows remote attackers to read form history by forging mouse and keyboard events that leverage the auto-fill feature to populate form fields, in an attacker-readable form, with history entries.

A Content Provider in Firefox for Android allowed local files accessible by the browser to be read by a remote webpage, leading to sensitive data disclosure, including cookies for other origins. This vulnerability affects Firefox for < Android.

Bugzilla 3.3.1 through 3.4.4, 3.5.1, and 3.5.2 does not allow group restrictions to be preserved throughout the process of moving a bug to a different product category, which allows remote attackers to obtain sensitive information via a request for a bug in opportunistic circumstances.

If a valid external protocol handler was referenced in an image tag, the resulting broken image size could be distinguished from a broken image size of a non-existent protocol handler. This allowed an attacker to successfully probe whether an external protocol handler was registered. This vulnerability affects Firefox < 82.

The find_replen function in jsstr.c in the Javascript engine for Mozilla Suite 1.7.6, Firefox 1.0.1 and 1.0.2, and Netscape 7.2 allows remote attackers to read portions of heap memory in a Javascript string via the lambda replace method.

Hashed codes of JavaScript objects are shared between pages. This allows for pointer leaks because an object's address can be discovered through hash codes, and also allows for data leakage of an object's content using these hash codes. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

Firefox before 1.0.1 and Mozilla before 1.7.6 does not restrict xsl:include and xsl:import tags in XSLT stylesheets to the current domain, which allows remote attackers to determine the existence of files on the local system.

Cross-origin images can be read in violation of the same-origin policy by exporting an image after using createImageBitmap to read the image and then rendering the resulting bitmap image within a canvas element. This vulnerability affects Firefox < 66.

Images from a different domain can be read using a canvas object in some circumstances. This could be used to steal image data from a different site in violation of same-origin policy. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.

Insufficient bounds checking of data during inter-process communication might allow a compromised content process to be able to read memory from the parent process under certain conditions. This vulnerability affects Firefox < 66.

dom/base/nsJSEnvironment.cpp in Mozilla Firefox 3.5.x before 3.5.11 and 3.6.x before 3.6.7, Thunderbird 3.0.x before 3.0.6 and 3.1.x before 3.1.1, and SeaMonkey before 2.0.6 does not properly suppress a script's URL in certain circumstances involving a redirect and an error message, which allows remote attackers to obtain sensitive information about script parameters via a crafted HTML document, related to the window.onerror handler.

Mozilla Mail 1.7.1 and 1.7.3, and Thunderbird before 0.9, when HTML-Mails is enabled, allows remote attackers to determine valid e-mail addresses via an HTML e-mail that references a Cascading Style Sheets (CSS) document on the attacker's server.

votes.cgi in Bugzilla 2.16.3 and earlier, and 2.17.1 through 2.17.4, allows remote attackers to read a user's voting page when that user has voted on a restricted bug, which allows remote attackers to read potentially sensitive voting information by modifying the who parameter.

Mozilla Necko, as used in Firefox, SeaMonkey, and other applications, performs DNS prefetching of domain names contained in links within local HTML documents, which makes it easier for remote attackers to determine the network location of the application's user by logging DNS requests. NOTE: the vendor disputes the significance of this issue, stating "I don't think we necessarily need to worry about that case."

Video files loaded video captions cross-origin without checking for the presence of CORS headers permitting such cross-origin use, leading to potential information disclosure for video captions. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

An attacker could use a JavaScript Map/Set timing attack to determine whether an atom is used by another compartment/zone in specific contexts. This could be used to leak information, such as usernames embedded in JavaScript code, across websites. This vulnerability affects Firefox < 50.1, Firefox ESR < 45.6, and Thunderbird < 45.6.

A previously installed malicious Android application which defines a specific signature-level permissions used by Firefox can access API keys meant for Firefox only. Note: This issue only affects Firefox for Android. Other versions and operating systems are unaffected. This vulnerability affects Firefox < 50.

External resources that should be blocked when loaded by SVG images can bypass security restrictions through the use of "data:" URLs. This could allow for cross-domain data leakage. This vulnerability affects Firefox < 50.1, Firefox ESR < 45.6, and Thunderbird < 45.6.

Content Security Policy combined with HTTP to HTTPS redirection can be used by malicious server to verify whether a known site is within a user's browser history. This vulnerability affects Firefox < 50.

A use-after-free vulnerability in SVG Animation has been discovered. An exploit built on this vulnerability has been discovered in the wild targeting Firefox and Tor Browser users on Windows. This vulnerability affects Firefox < 50.0.2, Firefox ESR < 45.5.1, and Thunderbird < 45.5.1.

The HTTPS protocol does not consider the role of the TCP congestion window in providing information about content length, which makes it easier for remote attackers to obtain cleartext data by leveraging a web-browser configuration in which third-party cookies are sent, aka a "HEIST" attack.