Native DOM methods can be hijacked across domains — Mozilla

A malicious page can hijack native DOM methods on a document object in another domain, which will run the attacker's script when called by the victim page. This could be used to steal login cookies, password, or other sensitive data on the target page, or to perform actions on behalf of a logged-...

PLUGINSPAGE privileged javascript execution — Mozilla

When a webpage requires a plugin that is not installed the user can click to launch the Plugin Finder Service PFS to find an appropriate plugin. If the service does not have an appropriate plugin the EMBED tag is checked for a PLUGINSPAGE attribute, and if one is found the PFS dialog will contain...

Security Vulnerabilities fixed in Firefox 139 — Mozilla

A double-free could have occurred in vpxcodecencinitmulti after a failed allocation when initializing the encoder for WebRTC. This could have caused memory corruption and a potentially exploitable crash. Error handling for script execution was incorrectly isolated from web content, which could ha...

Security Vulnerability fixed in Firefox 136.0.4, Firefox ESR 128.8.1, Firefox ESR 115.21.1 — Mozilla

Following the recent Chrome sandbox escape CVE-2025-2783, various Firefox developers identified a similar pattern in our IPC code. A compromised child process could cause the parent process to return an unintentionally powerful handle, leading to a sandbox escape. The original vulnerability was...

Security Vulnerabilities fixed in Thunderbird ESR 128.8 — Mozilla

Certain crafted MIME email messages that claimed to contain an encrypted OpenPGP message, which instead contained an OpenPGP signed message, were wrongly shown as being encrypted. When requesting an OpenPGP key from a WKD server, an incorrect padding size was used and a network observer could hav...

Security Vulnerabilities fixed in Firefox ESR 115.16 — Mozilla

A compromised content process could have allowed for the arbitrary loading of cross-origin pages. An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the resource://pdf.js origin. This could allow them to access cross-origin PDF content. This access i...

Security Issues fixed in Mozilla VPN for Linux v2.16.1 — Mozilla

An invalid Polkit Authentication check and missing authentication requirements for D-Bus methods allowed any local user to configure arbitrary VPN setups.This bug only affects Mozilla VPN on Linux. Other operating systems are unaffected...

Security Vulnerabilities fixed in Firefox ESR 91.1 — Mozilla

When delegating navigations to the operating system, Firefox would accept the mk scheme which might allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. This bug only affects Firefox for Windows. Other operating systems are unaffected. Mozilla developers...

Security Vulnerabilities fixed in Firefox for iOS 28 — Mozilla

A rogue webpage could override the injected WKUserScript used by the download feature, this exploit could result in the user downloading an unintended file. A rogue webpage could override the injected WKUserScript used by the logins autofill, this exploit could result in leaking a password for th...

Security Vulnerabilities fixed in Firefox for iOS 25 — Mozilla

For native-to-JS bridging, the app requires a unique token to be passed that ensures non-app code can't call the bridging functions. That token was being used for JS-to-native also, but it isn't needed in this case, and its usage was also leaking this token...

Security vulnerabilities fixed in - Thunderbird 68.1.1 — Mozilla

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...

Use-after-free in MediaStream playback — Mozilla

Security researcher SkyLined reported a use-after-free issue in how audio is handled through the Web Audio API during MediaStream playback through interactions with the Web Audio API. This results in a potentially exploitable crash...

Windows XP DLL loading vulnerability — Mozilla

Security researcher Haifei Li of FortiGuard Labs reported that Firefox could be used to load a malicious code library that had been planted on a victim's computer. Firefox attempts to load dwmapi.dll upon startup as part of its platform detection, so on systems that don't have this library, such ...

Characters mapped to U+FFFD in 8 bit encodings cause subsequent character to vanish — Mozilla

Security researcher O. Andersen reported that undefined positions within various 8 bit character encodings are mapped to the sequence U+FFFD which when displayed causes the immediately following character to disappear from the text run. This could potentially contribute to XSS problems on sites...

XSS using addEventListener and setTimeout on a wrapped object — Mozilla

Mozilla security researcher mozbugra4 reports that by using an appropriately wrapped object it was possible to bypass the fix for MFSA 2007-19. Prior to Firefox 3.6 this gives an attacker the ability to perform cross-site scripting attacks against arbitrary sites as in the original MFSA 2007-19...

Memory safety fixes in liboggplay media library — Mozilla

Mozilla discovered several bugs in liboggplay which posed potential memory safety issues. The bugs which were fixed could potentially be used by an attacker to crash a victim's browser and execute arbitrary code on their computer...

Location bar spoofing via tall line-height Unicode characters — Mozilla

Security researcher Juan Pablo Lopez Yacubian reported that the default Windows font used to render the locationbar and other text fields was improperly displaying certain Unicode characters with tall line-height. In such cases the tall line-height would cause the rest of the text in the input...

Crash and remote code execution using watch and __defineSetter__ on SVG element — Mozilla

Security researcher PenPal reported a crash involving a SVG element on which a watch function and defineSetter function have been set for a particular property. The crash showed evidence of memory corruption and could potentially be used by an attacker to run arbitrary code on a victim's computer...

Crash in nsTextFrame::ClearTextRun() — Mozilla

One of the security fixes in Firefox 3.0.9 introduced a regression that caused some users to experience frequent crashes. Users of the HTML Validator add-on were particularly affected, but other users also experienced this crash in some situations. In analyzing this crash we discovered that it wa...

Cross-domain data theft via script redirect error message — Mozilla

Google security researcher Chris Evans reported that a website could access a limited amount of data from a different domain by loading a same-domain JavaScript URL which redirects to an off-domain target resource containing data which is not parsable as JavaScript. Upon attempting to load the da...

XMLHttpRequest 302 response disclosure — Mozilla

Marius Schilder of Google Security reported that when a XMLHttpRequest is made to a same-origin resource which 302 redirects to a resource in a different domain, the response from the cross-domain resource is readable by the site issuing the XHR. Cookies marked HttpOnly were not readable, but oth...

XUL popup spoofing variant (cross-tab popups) — Mozilla

Mozilla contributor Chris Thomas demonstrated that it was possible to have a background tab create a borderless XUL pop-up in front of the active tab in the user's browser. This technique could be used by an attacker to spoof form elements such as a login prompt for a site opened in a different t...

Crashes with evidence of memory corruption (rv:1.8.1.5) — Mozilla

As part of the Firefox 2.0.0.5 update releases Mozilla developers fixed many bugs to improve the stability of the product. Some of these crashes that showed evidence of memory corruption under certain circumstances and we presume that with enough effort at least some of these could be exploited t...

Information disclosure through cache collisions — Mozilla

Aad reported that two web pages can collide in the disk cache with the result that depending on order loaded the end of the longer document can be appended to the shorter when the shorter is reloaded from the cache. It is possible a determined hacker could construct a targeted attack to steal som...

XSS using outer window's Function object — Mozilla

mozbugra4 demonstrated that the Function prototype regression described in bug 355161 could be exploited to bypass the protections against cross site script XSS injection, which could be used to steal credentials or sensitive data from arbitrary sites or perform destructive actions on behalf of a...

Heap buffer overwrite on malformed VCard — Mozilla

A VCard attachment with a malformed base64 field such as a photo can trigger a heap buffer overwrite. These have proven exploitable in the past, though in this case the overwrite is accompanied by an integer underflow that would attempt to copy more data than the typical machine has, leading to a...

Crashes with evidence of memory corruption (rv:1.8.0.5) — Mozilla

As part of the Firefox 1.5.0.5 stability and security release, developers in the Mozilla community looked for and fixed several crash bugs to improve the stability of Mozilla clients. Some of these crashes showed evidence of memory corruption that we presume could be exploited to run arbitrary co...

JavaScript new Function race condition — Mozilla

H. D. Moore reported a testcase that was able to trigger a race condition where JavaScript garbage collection deleted a temporary variable still being used in the creation of a new Function object. The resulting use of a deleted object may be potentially exploitable to run native code provided by...

"View Image" local resource linking (Windows) — Mozilla

Normally Mozilla-based clients prevent web content from linking to local files but Eric Foley reports a partial bypass of this restriction by using Windows filename syntax on a Windows computer rather than a file:/// URL as the SRC= attribute. The image will not be loaded on the web page--it will...

Web site XSS using BOM on UTF-8 pages — Mozilla

Masatoshi Kimura reports that the Unicode Byte-order-Mark BOM is stripped from UTF-8 pages during the conversion to Unicode before the parser sees the web page. As a result the parser will see and process script tags that web input sanitizers may miss because they appear as "scrBOMipt" or similar...

File stealing by changing input type — Mozilla

Claus Jörgensen reports that a text input box can be pre-filled with a filename and then turned into a file-upload control with the contents intact, allowing a malicious website the ability to steal any local file whose name they can guess...

"AnyName" entrainment and access control hazard — Mozilla

The implementation of E4X introduced an internal "AnyName" object which was unintentionally exposed to web content. This singleton object could be used by two cooperating domains as a communication channel to get around same-origin restrictions that prevent direct access from one window or frame ...

Changing position:relative to static corrupts memory — Mozilla

Dynamically changing the style of an element from position:relative to position:static can cause Gecko to operate on freed memory. It may be possible to exploit this in order to run arbitrary code...

Security Vulnerabilities fixed in Firefox for iOS 152.0 — Mozilla

Firefox for iOS used partial domain matching when attaching cookies to PDF requests, allowing a malicious site on a suffix domain to receive cookies belonging to the target site. Firefox for iOS preserved cookies set on the initial PDF request across cross-origin HTTP redirects in...

Security Vulnerabilities fixed in Firefox ESR 115.21 — Mozilla

In resizeToAtLeast of SkRegion.cpp, there was a possible out of bounds write due to an integer overflow On Windows, a compromised content process could use bad StreamData sent over AudioIPC to trigger a use-after-free in the Browser process. This could have led to a sandbox escape. It was possibl...

Security Vulnerabilities fixed in Firefox ESR 115.5.0 — Mozilla

On some systems—depending on the graphics settings and drivers—it was possible to force an out-of-bounds read and leak memory data into the images created on the canvas element. It was possible to cause the use of a MessagePort after it had already been freed, which could potentially have led to ...

Mozilla VPN local privilege escalation vis uncontrolled OpenSSL search path — Mozilla

Mozilla VPN can load an OpenSSL configuration file from an unsecured directory. A user or attacker with limited privileges could leverage this to launch arbitrary code with SYSTEM privilege...

Security Vulnerabilities fixed in Firefox ESR 68.5 — Mozilla

A content process could have modified shared memory relating to crash reporting information, crash itself, and cause an out-of-bound write. This could have caused memory corruption and a potentially exploitable crash. By downloading a file with the .fileloc extension, a semi-privileged extension...

Privilege escalation through file deletion by Maintenance Service updater — Mozilla

Security researcher Holger Fuhrmannek reported an issue where the Mozilla Maintenance Service updater on Windows can delete arbitrary files because of its privileged system access. This file deletion can then potentially be used for further privilege escalation. This flaw requires users to execut...

Android intents can be used on Firefox for Android to open privileged files — Mozilla

Security researcher Muneaki Nishimura reported that on Firefox for Android, a search engine can be registered and used to launch Firefox through an Android intent. When Firefox for Android is launched, the URL can executed with Firefox's system privileges if the crash reporter is used. This allow...

Crash when using shared memory in JavaScript — Mozilla

Security researcher Jukka Jylänki reported a crash that occurs because JavaScript, when using shared memory, does not properly gate access to Atomics or SharedArrayBuffer views in some contexts. This leads to a non-exploitable crash...

Miscellaneous memory safety hazards (rv:37.0 / rv:31.6) — Mozilla

Mozilla developers and community identified and fixed several memory safety bugs in the browser engine used in Firefox and other Mozilla-based products. Some of these bugs showed evidence of memory corruption under certain circumstances, and we presume that with enough effort at least some of the...

loadSubScript unwraps XPCNativeWrapper scope parameter (1.9.2 branch) — Mozilla

Mozilla security researcher mozbugra4 reported that the problem described in MFSA 2011-43 and fixed in Firefox 7 also affected Firefox 3.6: a malicious page could potentially exploit a Firefox user who had installed an add-on that used loadSubscript in vulnerable ways...

Heap buffer overflow in GIF color map parser — Mozilla

Security research firm iDefense reported that researcher regenrecht discovered a heap-based buffer overflow in Mozilla's GIF image parser. This vulnerability could potentially be used by an attacker to crash a victim's browser and run arbitrary code on their computer...

Chrome privilege escalation due to incorrectly cached wrapper — Mozilla

Mozilla add-on developer and community member Wladimir Palant reported broken functionality on pages that had a Link: HTTP header when an add-on was installed which implemented a Content Policy in JavaScript, such as AdBlock Plus or NoScript. Mozilla security researcher mozbugra4 demonstrated tha...

Race condition while accessing the private data of a NPObject JS wrapper class object — Mozilla

Jakob Balle and Carsten Eiram of Secunia Research reported a race condition in NPObjWrapperNewResolve when accessing the properties of a NPObject, a wrapped JSObject. Balle and Eiram demonstrated that this condition could be reached by navigating away from a web page during the loading of a Java...

XUL scripts bypass content-policy checks — Mozilla

Mozilla add-on developer and community member Wladimir Palant reported that content-loading policies were not checked before loading external script files into XUL documents. The severity of this problem would depend on the reasons behind the content policy check, which include privacy from "web...

Malicious search plugins can inject code into arbitrary sites — Mozilla

Security researcher Prateek Saxena reported that a malicious MozSearch plugin could be created using a javascript: URI in the SearchForm value. This URI is used as the default landing page when an empty search is performed. If an attacker could get a user to install the malicious plugin and perfo...

XSL Transformation vulnerability — Mozilla

Security researcher Guido Landi discovered that a XSL stylesheet could be used to crash the browser during a XSL transformation. An attacker could potentially use this crash to run arbitrary code on a victim's computer...

Local file stealing with SessionStore — Mozilla

Mozilla security researcher mozbugra4 reported that a form input control's type could be changed during the restoration of a closed tab. An attacker could set an input control's text value to the path of a local file whose location was known to the attacker. If the tab was then closed and the...