If right-to-left text is used in the addressbar with left-to-right alignment, it is possible in some circumstances to scroll this text to spoof the displayed URL. This issue could result in the wrong URL being displayed as a location, which can mislead users to believe they are on a different site than the one loaded. This vulnerability affects Thunderbird < 52.6, Firefox ESR < 52.6, and Firefox < 58.

Sites can bypass security checks on permissions to install lightweight themes by manipulating the "baseURI" property of the theme element. This could allow a malicious site to install a theme without user interaction which could contain offensive or embarrassing images. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

A lack of parameter validation on IPC messages results in a potential out-of-bounds write through malformed IPC messages. This can potentially allow for sandbox escape through memory corruption in the parent process. This vulnerability affects Thunderbird < 52.7, Firefox ESR < 52.7, and Firefox < 59.

If cursor visibility is toggled by script using from 'none' to an image and back through script, the cursor will be rendered temporarily invisible within Firefox. Note: This vulnerability only affects OS X. Other operating systems are not affected. This vulnerability affects Firefox < 58.

In the Windows 10 April 2018 Update, Windows Defender SmartScreen honors the "SEE_MASK_FLAG_NO_UI" flag associated with downloaded files and will not show any UI. Files that are unknown and potentially dangerous will be allowed to run because SmartScreen will not prompt the user for a decision, and if the user is offline all files will be allowed to be opened because Windows won't prompt the user to ask what to do. Firefox incorrectly sets this flag when downloading files, leading to less secure behavior from SmartScreen. Note: this issue only affects Windows 10 users running the April 2018 update or later. It does not affect other Windows users or other operating systems. This vulnerability affects Thunderbird < 52.8, Thunderbird ESR < 52.8, Firefox < 60, and Firefox ESR < 52.8.

Documents formed using data: URLs in an OBJECT element failed to inherit the CSP of the creating context. This allowed the execution of scripts that should have been blocked, albeit with a unique opaque origin. This vulnerability affects Firefox < 76.

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.

email_in.pl in Bugzilla 2.23.4 through 3.0.0 allows remote attackers to execute arbitrary commands via the -f (From address) option to the Email::Send::Sendmail function, probably involving shell metacharacters.

A crafted S/MIME message consisting of an inner encryption layer and an outer SignedData layer was shown as having a valid digital signature, although the signer might have had no access to the contents of the encrypted message, and might have stripped a different signature from the encrypted message. Previous versions had only suppressed showing a digital signature for messages with an outer multipart/signed layer. This vulnerability affects Thunderbird < 68.1.1.

If WebRTC permission is requested from documents with data: or blob: URLs, the permission notifications do not properly display the originating domain. The notification states "Unknown origin" as the requestee, leading to user confusion about which site is asking for this permission. This vulnerability affects Firefox < 66.

Manually dragging and dropping an Outlook email message into the browser will trigger a page navigation when the message's mail columns are incorrectly interpreted as a URL. *Note: this issue only affects Windows operating systems with Outlook installed. Other operating systems are not affected.*. This vulnerability affects Firefox ESR < 60.2 and Firefox < 62.

Mozilla Firefox before 5.0 does not properly enforce the whitelist for the xpinstall functionality, which allows remote attackers to trigger an installation dialog for a (1) add-on or (2) theme via unspecified vectors.

Mozilla Firefox before 3.6.18, Thunderbird before 3.1.11, and SeaMonkey through 2.0.14 do not distinguish between cookies for two domain names that differ only in a trailing dot, which allows remote web servers to bypass the Same Origin Policy via Set-Cookie headers.

Auth/Verify/LDAP.pm in Bugzilla 2.x and 3.x before 3.6.11, 3.7.x and 4.0.x before 4.0.8, 4.1.x and 4.2.x before 4.2.3, and 4.3.x before 4.3.3 does not restrict the characters in a username, which might allow remote attackers to inject data into an LDAP directory via a crafted login attempt.

If a site is loaded over a HTTPS connection but loads a favicon resource over HTTP, the mixed content warning is not displayed to users. This vulnerability affects Firefox < 63.

The displayed addressbar URL can be spoofed on Firefox for Android using a javascript: URI in concert with JavaScript to insert text before the loaded domain name, scrolling the loaded domain out of view to the right. This can lead to user confusion. *This vulnerability only affects Firefox for Android < 62.*

Mozilla Firefox 2.0.0.1 through 2.0.0.3 does not canonicalize URLs before checking them against the phishing site blacklist, which allows remote attackers to bypass phishing protection via multiple / (slash) characters in the URL.

Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderbird ESR 10.x before 10.0.12 and 17.x before 17.0.2, and SeaMonkey before 2.15 allow remote attackers to spoof the address bar via vectors involving authentication information in the userinfo field of a URL, in conjunction with a 204 (aka No Content) HTTP status code.

An audio capture session can started under an incorrect origin from the site making the capture request. Users are still prompted to allow the request but the prompt can display the wrong origin, leading to user confusion about which site is making the request to capture an audio stream. This vulnerability affects Firefox < 58.

Punycode format text will be displayed for entire qualified international domain names in some instances when a sub-domain triggers the punycode display instead of the primary domain being displayed in native script and the sub-domain only displaying as punycode. This could be used for limited spoofing attacks due to user confusion. This vulnerability affects Firefox < 57.

A spoofing vulnerability can occur when a page switches to fullscreen mode without user notification, allowing a fake address bar to be displayed. This allows an attacker to spoof which page is actually loaded and in use. Note: This attack only affects Firefox for Android. Other operating systems are not affected. This vulnerability affects Firefox < 56.

Several fonts on OS X display some Tibetan and Arabic characters as whitespace. When used in the addressbar as part of an IDN this can be used for domain name spoofing attacks. Note: This attack only affects OS X operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4.

Default fonts on OS X display some Tibetan characters as whitespace. When used in the addressbar as part of an IDN this can be used for domain name spoofing attacks. Note: This attack only affects OS X operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.

The "instanceof" operator can bypass the Xray wrapper mechanism. When called on web content from the browser itself or an extension the web content can provide its own result for that operator, possibly tricking the browser or extension into mishandling the element. This vulnerability affects Firefox < 56.

The combined, single character, version of the letter 'i' with any of the potential accents in unicode, such as acute or grave, can be spoofed in the addressbar by the dotless version of 'i' followed by the same accent as a second character with most font sets. This allows for domain spoofing attacks because these combined domain names do not display as punycode. This vulnerability affects Firefox < 57.

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.

When a page's content security policy (CSP) header contains a "sandbox" directive, other directives are ignored. This results in the incorrect enforcement of CSP. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

RSS fields can inject new lines into the created email structure, modifying the message body. This vulnerability affects Thunderbird < 52.5.2.

Mozilla Firefox 4.x through 13.0, Firefox ESR 10.x before 10.0.6, Thunderbird 5.0 through 13.0, Thunderbird ESR 10.x before 10.0.6, and SeaMonkey before 2.11 do not consider the presence of same-compartment security wrappers (SCSW) during the cross-compartment wrapping of objects, which allows remote attackers to bypass intended XBL access restrictions via crafted content.

An error in the "WindowsDllDetourPatcher" where a RWX ("Read/Write/Execute") 4k block is allocated but never protected, violating DEP protections. Note: This attack only affects Windows operating systems. Other operating systems are not affected. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

SVG loaded through "<img>" tags can use "<meta>" tags within the SVG data to set cookies for that page. This vulnerability affects Firefox < 57.

Characters from the "Canadian Syllabics" unicode block can be mixed with characters from other unicode blocks in the addressbar instead of being rendered as their raw "punycode" form, allowing for domain name spoofing attacks through character confusion. The current Unicode standard allows characters from "Aspirational Use Scripts" such as Canadian Syllabics to be mixed with Latin characters in the "moderately restrictive" IDN profile. We have changed Firefox behavior to match the upcoming Unicode version 10.0 which removes this category and treats them as "Limited Use Scripts.". This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.

When entered directly, Reader Mode did not strip the username and password section of URLs displayed in the addressbar. This can be used for spoofing the domain of the current page. This vulnerability affects Firefox < 54.

If a server sends two Strict-Transport-Security (STS) headers for a single connection, they will be rejected as invalid and HTTP Strict Transport Security (HSTS) will not be enabled for the connection. This vulnerability affects Firefox < 55.

Some Arabic and Indic vowel marker characters can be combined with Latin characters in a domain name to eclipse the non-Latin character with some font sets on the addressbar. The non-Latin character will not be visible to most viewers. This allows for domain spoofing attacks because these combined domain names do not display as punycode. This vulnerability affects Firefox < 57.

A flaw in DRBG number generation within the Network Security Services (NSS) library where the internal state V does not correctly carry bits over. The NSS library has been updated to fix this issue to address this issue and Firefox ESR 52.1 has been updated with NSS version 3.28.4. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.

An attack can use a blob URL and script to spoof an arbitrary addressbar URL prefaced by "blob:" as the protocol, leading to user confusion and further spoofing attacks. This vulnerability affects Firefox < 52.

When dragging content from the primary browser pane to the addressbar on a malicious site, it is possible to change the addressbar so that the displayed location following navigation does not match the URL of the newly loaded page. This allows for spoofing attacks. This vulnerability affects Firefox < 52.

URLs containing certain unicode glyphs for alternative hyphens and quotes do not properly trigger punycode display, allowing for domain name spoofing attacks in the location bar. This vulnerability affects Thunderbird < 45.7, Firefox ESR < 45.7, and Firefox < 51.

Firefox will accept any registered Program ID as an external protocol handler and offer to launch this local application when given a matching URL on Windows operating systems. This should only happen if the program has specifically registered itself as a "URL Handler" in the Windows registry. *Note: This issue only affects Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

The internal feed reader APIs that crossed the sandbox barrier allowed for a sandbox escape and escalation of privilege if combined with another vulnerability that resulted in remote code execution inside the sandboxed process. This vulnerability affects Firefox ESR < 52.1 and Firefox < 53.

The "export" function in the Certificate Viewer can force local filesystem navigation when the "common name" in a certificate contains slashes, allowing certificate content to be saved in unsafe locations with an arbitrary filename. This vulnerability affects Firefox < 51.

Android intents can be used to launch Firefox for Android in reader mode with a user specified URL. This allows an attacker to spoof the contents of the addressbar as displayed to users. Note: This attack only affects Firefox for Android. Other operating systems are not affected. This vulnerability affects Firefox < 53.

A mechanism to spoof the Firefox for Android addressbar using a "javascript:" URI. On Firefox for Android, the base domain is parsed incorrectly, making the resulting location less visibly a spoofed site and showing an incorrect domain in appended notifications. This vulnerability affects Firefox < 53.

A malicious site could spoof the contents of the print preview window if popup windows are enabled, resulting in user confusion of what site is currently loaded. This vulnerability affects Firefox < 52 and Thunderbird < 52.

On Linux, if the secure computing mode BPF (seccomp-bpf) filter is running when the Gecko Media Plugin sandbox is started, the sandbox fails to be applied and items that would run within the sandbox are run protected only by the running filter which is typically weak compared to the sandbox. Note: this issue only affects Linux. Other operating systems are not affected. This vulnerability affects Firefox < 52 and Thunderbird < 52.

Mozilla Firefox 4.x through 9.0, Thunderbird 5.0 through 9.0, and SeaMonkey before 2.7 allow remote attackers to bypass the HTML5 frame-navigation policy and replace arbitrary sub-frames by creating a form submission target with a sub-frame's name attribute.

Bugzilla 2.16rc1 through 2.22.7, 3.0.x through 3.3.x, 3.4.x before 3.4.12, 3.5.x, 3.6.x before 3.6.6, 3.7.x, 4.0.x before 4.0.2, and 4.1.x before 4.1.3 does not prevent changes to the confirmation e-mail address (aka old_email field) for e-mail change notifications, which makes it easier for remote attackers to perform arbitrary address changes by leveraging an unattended workstation.

The CSSLoaderImpl::DoSheetComplete function in layout/style/nsCSSLoader.cpp in Mozilla Firefox 3.0.x before 3.0.18, 3.5.x before 3.5.8, and 3.6.x before 3.6.2; Thunderbird before 3.0.2; and SeaMonkey before 2.0.3 changes the case of certain strings in a stylesheet before adding this stylesheet to the XUL cache, which might allow remote attackers to modify the browser's font and other CSS attributes, and potentially disrupt rendering of a web page, by forcing the browser to perform this erroneous stylesheet caching.

Mozilla Firefox before 2.0.0.15 and SeaMonkey before 1.1.10 allow remote attackers to force the upload of arbitrary local files from a client computer via vectors involving originalTarget and DOM Range.