Vulnerabilities (CVE)

The "Forget about this site" feature in the History pane is intended to remove all saved user data that indicates a user has visited a site. This includes removing any HTTP Strict Transport Security (HSTS) settings received from sites that use it. Due to a bug, sites on the pre-load list also have their HSTS setting removed. On the next visit to that site if the user specifies an http: URL rather than secure https: they will not be protected by the pre-loaded HSTS setting. After that visit the s ... The "Forget about this site" feature in the History pane is intended to remove all saved user data that indicates a user has visited a site. This includes removing any HTTP Strict Transport Security (HSTS) settings received from sites that use it. Due to a bug, sites on the pre-load list also have their HSTS setting removed. On the next visit to that site if the user specifies an http: URL rather than secure https: they will not be protected by the pre-loaded HSTS setting. After that visit the site's HSTS setting will be restored. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

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When encrypting with a block cipher, if a call to NSC_EncryptUpdate was made with data smaller than the block size, a small out of bounds write could occur. This could have caused heap corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.

A compromised sandboxed content process can perform a Universal Cross-site Scripting (UXSS) attack on content from any site it can cause to be loaded in the same process. Because addons.mozilla.org and accounts.firefox.com have close ties to the Firefox product, malicious manipulation of these sites within the browser can potentially be used to modify a user's Firefox configuration. These two sites will now be isolated into their own process and not allowed to be loaded in a standard content pro ... A compromised sandboxed content process can perform a Universal Cross-site Scripting (UXSS) attack on content from any site it can cause to be loaded in the same process. Because addons.mozilla.org and accounts.firefox.com have close ties to the Firefox product, malicious manipulation of these sites within the browser can potentially be used to modify a user's Firefox configuration. These two sites will now be isolated into their own process and not allowed to be loaded in a standard content process. This vulnerability affects Firefox < 69.

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If a Content Security Policy (CSP) directive is defined that uses a hash-based source that takes the empty string as input, execution of any javascript: URIs will be allowed. This could allow for malicious JavaScript content to be run, bypassing CSP permissions. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

If a wildcard ('*') is specified for the host in Content Security Policy (CSP) directives, any port or path restriction of the directive will be ignored, leading to CSP directives not being properly applied to content. This vulnerability affects Firefox < 69.

The Mozilla Maintenance Service does not guard against files being hardlinked to another file in the updates directory, allowing for the replacement of local files, including the Maintenance Service executable, which is run with privileged access. Additionally, there was a race condition during checks for junctions and symbolic links by the Maintenance Service, allowing for potential local file and directory manipulation to be undetected in some circumstances. This allows for potential privilege ... The Mozilla Maintenance Service does not guard against files being hardlinked to another file in the updates directory, allowing for the replacement of local files, including the Maintenance Service executable, which is run with privileged access. Additionally, there was a race condition during checks for junctions and symbolic links by the Maintenance Service, allowing for potential local file and directory manipulation to be undetected in some circumstances. This allows for potential privilege escalation by a user with unprivileged local access. <br>*Note: These attacks requires local system access and only affects Windows. Other operating systems are not affected.*. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

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Mozilla developers and community members reported memory safety bugs present in Firefox 68 and Firefox ESR 68. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

Mozilla developers and community members reported memory safety bugs present in Firefox 68. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 69.

A vulnerability exists where if a user opens a locally saved HTML file, this file can use file: URIs to access other files in the same directory or sub-directories if the names are known or guessed. The Fetch API can then be used to read the contents of any files stored in these directories and they may uploaded to a server. It was demonstrated that in combination with a popular Android messaging app, if a malicious HTML attachment is sent to a user and they opened that attachment in Firefox, du ... A vulnerability exists where if a user opens a locally saved HTML file, this file can use file: URIs to access other files in the same directory or sub-directories if the names are known or guessed. The Fetch API can then be used to read the contents of any files stored in these directories and they may uploaded to a server. It was demonstrated that in combination with a popular Android messaging app, if a malicious HTML attachment is sent to a user and they opened that attachment in Firefox, due to that app's predictable pattern for locally-saved file names, it is possible to read attachments the victim received from other correspondents. This vulnerability affects Firefox ESR < 60.8, Firefox < 68, and Thunderbird < 60.8.

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The HTTP Alternative Services header, Alt-Svc, can be used by a malicious site to scan all TCP ports of any host that the accessible to a user when web content is loaded. This vulnerability affects Firefox < 68.

A vulnerability exists where it possible to force Network Security Services (NSS) to sign CertificateVerify with PKCS#1 v1.5 signatures when those are the only ones advertised by server in CertificateRequest in TLS 1.3. PKCS#1 v1.5 signatures should not be used for TLS 1.3 messages. This vulnerability affects Firefox < 68.

When a user navigates to site marked as unsafe by the Safebrowsing API, warning messages are displayed and navigation is interrupted but resources from the same site loaded through websockets are not blocked, leading to the loading of unsafe resources and bypassing safebrowsing protections. This vulnerability affects Firefox < 68.

Application permissions give additional remote troubleshooting permission to the site input.mozilla.org, which has been retired and now redirects to another site. This additional permission is unnecessary and is a potential vector for malicious attacks. This vulnerability affects Firefox < 68.

A vulnerability exists during the installation of add-ons where the initial fetch ignored the origin attributes of the browsing context. This could leak cookies in private browsing mode or across different "containers" for people who use the Firefox Multi-Account Containers Web Extension. This vulnerability affects Firefox < 68.

The unicode latin 'kra' character can be used to spoof a standard 'k' character in the addressbar. This allows for domain spoofing attacks as do not display as punycode text, allowing for user confusion. This vulnerability affects Firefox < 68.

Some unicode characters are incorrectly treated as whitespace during the parsing of web content instead of triggering parsing errors. This allows malicious code to then be processed, evading cross-site scripting (XSS) filtering. This vulnerability affects Firefox < 68.

Activity Stream can display content from sent from the Snippet Service website. This content is written to innerHTML on the Activity Stream page without sanitization, allowing for a potential access to other information available to the Activity Stream, such as browsing history, if the Snipper Service were compromised. This vulnerability affects Firefox < 68.

Until explicitly accessed by script, window.globalThis is not enumerable and, as a result, is not visible to code such as Object.getOwnPropertyNames(window). Sites that deploy a sandboxing that depends on enumerating and freezing access to the window object may miss this, allowing their sandboxes to be bypassed. This vulnerability affects Firefox < 68.

Necko can access a child on the wrong thread during UDP connections, resulting in a potentially exploitable crash in some instances. This vulnerability affects Firefox < 68.

Mozilla developers and community members reported memory safety bugs present in Firefox 67. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 68.

A hyperlink using protocols associated with Internet Explorer, such as IE.HTTP:, can be used to open local files at a known location with Internet Explorer if a user approves execution when prompted. *Note: this issue only occurs on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 67.0.2.

The default webcal: protocol handler will load a web site vulnerable to cross-site scripting (XSS) attacks. This default was left in place as a legacy feature and has now been removed. *Note: this issue only affects users with an account on the vulnerable service. Other users are unaffected.*. This vulnerability affects Firefox < 67.

A hyperlink using the res: protocol can be used to open local files at a known location in Internet Explorer if a user approves execution when prompted. *Note: this issue only occurs on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 67.

A malicious page can briefly cause the wrong name to be highlighted as the domain name in the addressbar during page navigations. This could result in user confusion of which site is currently loaded for spoofing attacks. This vulnerability affects Firefox < 67.

If the ALT and "a" keys are pressed when users receive an extension installation prompt, the extension will be installed without the install prompt delay that keeps the prompt visible in order for users to accept or decline the installation. A malicious web page could use this with spoofing on the page to trick users into installing a malicious extension. This vulnerability affects Firefox < 67.

Files with the .JNLP extension used for "Java web start" applications are not treated as executable content for download prompts even though they can be executed if Java is installed on the local system. This could allow users to mistakenly launch an executable binary locally. This vulnerability affects Firefox < 67.

A custom cursor defined by scripting on a site can position itself over the addressbar to spoof the actual cursor when it should not be allowed outside of the primary web content area. This could be used by a malicious site to trick users into clicking on permission prompts, doorhanger notifications, or other buttons inadvertently if the location is spoofed over the user interface. This vulnerability affects Firefox < 67.

A use-after-free vulnerability can occur when working with XMLHttpRequest (XHR) in an event loop, causing the XHR main thread to be called after it has been freed. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.

In Apache Spark 2.1.0 to 2.1.2, 2.2.0 to 2.2.1, and 2.3.0, it's possible for a malicious user to construct a URL pointing to a Spark cluster's UI's job and stage info pages, and if a user can be tricked into accessing the URL, can be used to cause script to execute and expose information from the user's view of the Spark UI. While some browsers like recent versions of Chrome and Safari are able to block this type of attack, current versions of Firefox (and possibly others) do not.

Memory safety bugs present in Firefox 60, Firefox ESR 60, and Firefox ESR 52.8. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

Memory safety bugs present in Firefox 60. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 61.

If a text string that happens to be a filename in the operating system's native format is dragged and dropped onto the addressbar the specified local file will be opened. This is contrary to policy and is what would happen if the string were the equivalent "file:" URL. This vulnerability affects Firefox < 60.

If a URL using the "file:" protocol is dragged and dropped onto an open tab that is running in a different child process the tab will open a local file corresponding to the dropped URL, contrary to policy. One way to make the target tab open more reliably in a separate process is to open it with the "noopener" keyword. This vulnerability affects Firefox < 60.

A use-after-free vulnerability can occur during WebGL operations. While this results in a potentially exploitable crash, the vulnerability is limited because the memory is freed and reused in a brief window of time during the freeing of the same callstack. This vulnerability affects Firefox < 60.

A service worker can send the activate event on itself periodically which allows it to run perpetually, allowing it to monitor activity by users. Affects all versions prior to Firefox 60.

A vulnerability exists in XSLT during number formatting where a negative buffer size may be allocated in some instances, leading to a buffer overflow and crash if it occurs. This vulnerability affects Firefox < 60.

The JSON Viewer displays clickable hyperlinks for strings that are parseable as URLs, including "javascript:" links. If a JSON file contains malicious JavaScript script embedded as "javascript:" links, users may be tricked into clicking and running this code in the context of the JSON Viewer. This can allow for the theft of cookies and authorization tokens which are accessible to that context. This vulnerability affects Firefox < 60.

A mechanism to bypass Content Security Policy (CSP) protections on sites that have a "script-src" policy of "'strict-dynamic'". If a target website contains an HTML injection flaw an attacker could inject a reference to a copy of the "require.js" library that is part of Firefox's Developer Tools, and then use a known technique using that library to bypass the CSP restrictions on executing injected scripts. This vulnerability affects Firefox < 60.

The filename appearing in the "Downloads" panel improperly renders some Unicode characters, allowing for the file name to be spoofed. This can be used to obscure the file extension of potentially executable files from user view in the panel. Note: the dialog to open the file will show the full, correct filename and whether it is executable or not. This vulnerability affects Firefox < 60.

The Live Bookmarks page and the PDF viewer can run injected script content if a user pastes script from the clipboard into them while viewing RSS feeds or PDF files. This could allow a malicious site to socially engineer a user to copy and paste malicious script content that could then run with the context of either page but does not allow for privilege escalation. This vulnerability affects Firefox < 60.