Exposure of Sensitive Information to an Unauthorized Actor

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.Show less

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.Show less

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.Show less

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.Show less

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.Show less

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.Show less

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.Show less

The Mozilla Maintenance Service can be invoked by an unprivileged user to read 32 bytes of any arbitrary file on the local system by convincing the service that it is reading a status file provided by the Mozilla Windows Updater. The Mozilla Maintenance Service executes with privileged access, bypassing system protections against unprivileged users. Note: This attack requires local system access and only affects Windows. Other operating systems are not affected. This vulnerability affects Firefox ESR < 52.2 and Firefox < 54.Show less

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.Show less

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.Show less

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.Show less

The file picker dialog can choose and display the wrong local default directory when instantiated. On some operating systems, this can lead to information disclosure, such as the operating system or the local account name. This vulnerability affects Firefox < 52 and Thunderbird < 52.Show less

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.Show less

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.Show less

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.Show less

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.Show less

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.Show less

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.Show less

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.Show less