A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash. This vulnerability affects Firefox < 67.

This update for MozillaFirefox fixes the following issues :

MozillaFirefox was updated to 60.7.0esr (boo#1135824 MFSA 2019-14) :

  - CVE-2018-18511: Cross-origin theft of images with     ImageBitmapRenderingContext

  - CVE-2019-11691: Use-after-free in XMLHttpRequest

  - CVE-2019-11692: Use-after-free removing listeners in the     event listener manager

  - CVE-2019-11693: Buffer overflow in WebGL bufferdata on     Linux

  - CVE-2019-11694: (Windows only) Uninitialized memory     memory leakage in Windows sandbox

  - CVE-2019-11698: Theft of user history data through drag     and drop of hyperlinks to and from bookmarks

  - CVE-2019-5798: Out-of-bounds read in Skia

  - CVE-2019-7317: Use-after-free in png_image_free of     libpng library

  - CVE-2019-9797: Cross-origin theft of images with     createImageBitmap

  - CVE-2019-9800: Memory safety bugs fixed in Firefox 67     and Firefox ESR 60.7

  - CVE-2019-9815: Disable hyperthreading on content     JavaScript threads on macOS

  - CVE-2019-9816: Type confusion with object groups and     UnboxedObjects

  - CVE-2019-9817: Stealing of cross-domain images using     canvas

  - CVE-2019-9818: (Windows only) Use-after-free in crash     generation server

  - CVE-2019-9819: Compartment mismatch with fetch API

  - CVE-2019-9820: Use-after-free of ChromeEventHandler by     DocShell

  - CVE-2019-9821: Use-after-free in AssertWorkerThread

The version of Firefox installed on the remote Windows host is prior to 67.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2019-13 advisory.

  - If hyperthreading is not disabled, a timing attack     vulnerability exists, similar to previous Spectre     attacks. Apple has shipped macOS 10.14.5 with an option     to disable hyperthreading in applications running     untrusted code in a thread through a new sysctl. Firefox     now makes use of it on the main thread and any worker     threads. Note: users need to update to macOS 10.14.5     in order to take advantage of this change.
    (CVE-2019-9815)

  - A possible vulnerability exists where type confusion can     occur when manipulating JavaScript objects in object     groups, allowing for the bypassing of security checks     within these groups. Note: this vulnerability has     only been demonstrated with UnboxedObjects,     which are disabled by default on all supported releases.
    (CVE-2019-9816)

  - 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. (CVE-2019-9817)

  - A race condition is present in the crash generation     server used to generate data for the crash reporter.
    This issue can lead to a use-after-free in the main     process, resulting in a potentially exploitable crash     and a sandbox escape. Note: this vulnerability only     affects Windows. Other operating systems are unaffected.
    (CVE-2019-9818)

  - A vulnerability where a JavaScript compartment mismatch     can occur while working with the fetch API,     resulting in a potentially exploitable crash.
    (CVE-2019-9819)

  - A use-after-free vulnerability can occur in the chrome     event handler when it is freed while still in use. This     results in a potentially exploitable crash.
    (CVE-2019-9820)

  - A use-after-free vulnerability can occur in     AssertWorkerThread due to a race condition     with shared workers. This results in a potentially     exploitable crash. (CVE-2019-9821)

  - 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. (CVE-2019-11691)

  - A use-after-free vulnerability can occur when listeners     are removed from the event listener manager while still     in use, resulting in a potentially exploitable crash.
    (CVE-2019-11692)

  - The bufferdata function in WebGL is     vulnerable to a buffer overflow with specific graphics     drivers on Linux. This could result in malicious content     freezing a tab or triggering a potentially exploitable     crash. Note: this issue only occurs on Linux. Other     operating systems are unaffected. (CVE-2019-11693)

  - A use-after-free vulnerability was discovered in the     pngimagefree function in the libpng     library. This could lead to denial of service or a     potentially exploitable crash when a malformed image is     processed. (CVE-2019-7317)

  - A vulnerability exists in the Windows sandbox where an     uninitialized value in memory can be leaked to a     renderer from a broker when making a call to access an     otherwise unavailable file. This results in the     potential leaking of information stored at that memory     location. Note: this issue only occurs on Windows.
    Other operating systems are unaffected. (CVE-2019-11694)

  - 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. (CVE-2019-11695)

  - 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. (CVE-2019-11696)

  - 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.
    (CVE-2019-11697)

  - 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. (CVE-2019-11698)

  - 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. (CVE-2019-11700)

  - 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.
    (CVE-2019-11699)

  - 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. (CVE-2019-11701)

  - Mozilla developers and community members Christian     Holler, Andrei Ciure, Julien Cristau, Jan de Mooij, Jan     Varga, Marcia Knous, Andr Bargull, and Philipp reported     memory safety bugs present in Firefox 66. 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. (CVE-2019-9814)

  - Mozilla developers and community members Olli Pettay,     Bogdan Tara, Jan de Mooij, Jason Kratzer, Jan Varga,     Gary Kwong, Tim Guan-tin Chien, Tyson Smith, Ronald     Crane, and Ted Campbell reported memory safety bugs     present in Firefox 66 and Firefox ESR 60.6. 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. (CVE-2019-9800)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of Firefox installed on the remote macOS or Mac OS X host is prior to 67.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2019-13 advisory.

  - If hyperthreading is not disabled, a timing attack     vulnerability exists, similar to previous Spectre     attacks. Apple has shipped macOS 10.14.5 with an option     to disable hyperthreading in applications running     untrusted code in a thread through a new sysctl. Firefox     now makes use of it on the main thread and any worker     threads. Note: users need to update to macOS 10.14.5     in order to take advantage of this change.
    (CVE-2019-9815)

  - A possible vulnerability exists where type confusion can     occur when manipulating JavaScript objects in object     groups, allowing for the bypassing of security checks     within these groups. Note: this vulnerability has     only been demonstrated with UnboxedObjects,     which are disabled by default on all supported releases.
    (CVE-2019-9816)

  - 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. (CVE-2019-9817)

  - A race condition is present in the crash generation     server used to generate data for the crash reporter.
    This issue can lead to a use-after-free in the main     process, resulting in a potentially exploitable crash     and a sandbox escape. Note: this vulnerability only     affects Windows. Other operating systems are unaffected.
    (CVE-2019-9818)

  - A vulnerability where a JavaScript compartment mismatch     can occur while working with the fetch API,     resulting in a potentially exploitable crash.
    (CVE-2019-9819)

  - A use-after-free vulnerability can occur in the chrome     event handler when it is freed while still in use. This     results in a potentially exploitable crash.
    (CVE-2019-9820)

  - A use-after-free vulnerability can occur in     AssertWorkerThread due to a race condition     with shared workers. This results in a potentially     exploitable crash. (CVE-2019-9821)

  - 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. (CVE-2019-11691)

  - A use-after-free vulnerability can occur when listeners     are removed from the event listener manager while still     in use, resulting in a potentially exploitable crash.
    (CVE-2019-11692)

  - The bufferdata function in WebGL is     vulnerable to a buffer overflow with specific graphics     drivers on Linux. This could result in malicious content     freezing a tab or triggering a potentially exploitable     crash. Note: this issue only occurs on Linux. Other     operating systems are unaffected. (CVE-2019-11693)

  - A use-after-free vulnerability was discovered in the     pngimagefree function in the libpng     library. This could lead to denial of service or a     potentially exploitable crash when a malformed image is     processed. (CVE-2019-7317)

  - A vulnerability exists in the Windows sandbox where an     uninitialized value in memory can be leaked to a     renderer from a broker when making a call to access an     otherwise unavailable file. This results in the     potential leaking of information stored at that memory     location. Note: this issue only occurs on Windows.
    Other operating systems are unaffected. (CVE-2019-11694)

  - 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. (CVE-2019-11695)

  - 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. (CVE-2019-11696)

  - 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.
    (CVE-2019-11697)

  - 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. (CVE-2019-11698)

  - 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. (CVE-2019-11700)

  - 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.
    (CVE-2019-11699)

  - 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. (CVE-2019-11701)

  - Mozilla developers and community members Christian     Holler, Andrei Ciure, Julien Cristau, Jan de Mooij, Jan     Varga, Marcia Knous, Andr Bargull, and Philipp reported     memory safety bugs present in Firefox 66. 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. (CVE-2019-9814)

  - Mozilla developers and community members Olli Pettay,     Bogdan Tara, Jan de Mooij, Jason Kratzer, Jan Varga,     Gary Kwong, Tim Guan-tin Chien, Tyson Smith, Ronald     Crane, and Ted Campbell reported memory safety bugs     present in Firefox 66 and Firefox ESR 60.6. 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. (CVE-2019-9800)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Mozilla Foundation reports :

CVE-2019-9815: Disable hyperthreading on content JavaScript threads on macOS

CVE-2019-9816: Type confusion with object groups and UnboxedObjects

CVE-2019-9817: Stealing of cross-domain images using canvas

CVE-2019-9818: Use-after-free in crash generation server

CVE-2019-9819: Compartment mismatch with fetch API

CVE-2019-9820: Use-after-free of ChromeEventHandler by DocShell

CVE-2019-9821: Use-after-free in AssertWorkerThread

CVE-2019-11691: Use-after-free in XMLHttpRequest

CVE-2019-11692: Use-after-free removing listeners in the event listener manager

CVE-2019-11693: Buffer overflow in WebGL bufferdata on Linux

CVE-2019-7317: Use-after-free in png_image_free of libpng library

CVE-2019-11694: Uninitialized memory memory leakage in Windows sandbox

CVE-2019-11695: Custom cursor can render over user interface outside of web content

CVE-2019-11696: Java web start .JNLP files are not recognized as executable files for download prompts

CVE-2019-11697: Pressing key combinations can bypass installation prompt delays and install extensions

CVE-2019-11698: Theft of user history data through drag and drop of hyperlinks to and from bookmarks

CVE-2019-11700: res: protocol can be used to open known local files

CVE-2019-11699: Incorrect domain name highlighting during page navigation

CVE-2019-11701: webcal: protocol default handler loads vulnerable web page

CVE-2019-9814: Memory safety bugs fixed in Firefox 67

CVE-2019-9800: Memory safety bugs fixed in Firefox 67 and Firefox ESR 60.7

The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-3991-1 advisory.

    Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially     crafted website, an attacker could potentially exploit these to cause a denial of service, spoof the     browser UI, trick the user in to launching local executable binaries, obtain sensitive information,     conduct cross-site scripting (XSS) attacks, or execute arbitrary code. (CVE-2019-11691, CVE-2019-11692,     CVE-2019-11693, CVE-2019-11695, CVE-2019-11696, CVE-2019-11699, CVE-2019-11701, CVE-2019-7317,     CVE-2019-9800, CVE-2019-9814, CVE-2019-9817, CVE-2019-9819, CVE-2019-9820, CVE-2019-9821)

    It was discovered that pressing certain key combinations could bypass addon installation prompt delays. If     a user opened a specially crafted website, an attacker could potentially exploit this to trick them in to     installing a malicious extension. (CVE-2019-11697)

    It was discovered that history data could be exposed via drag and drop of hyperlinks to and from     bookmarks. If a user were tricked in to dragging a specially crafted hyperlink to the bookmark toolbar or     sidebar, and subsequently back in to the web content area, an attacker could potentially exploit this to     obtain sensitive information. (CVE-2019-11698)

    A type confusion bug was discovered with object groups and UnboxedObjects. If a user were tricked in to     opening a specially crafted website after enabling the UnboxedObjects feature, an attacker could     potentially exploit this to bypass security checks. (CVE-2019-9816)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Firefox installed on the remote host is prior to 67.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2019-13 advisory:

 - If hyperthreading is not disabled, a timing attack vulnerability exists, similar to previous Spectre attacks. Apple has shipped macOS 10.14.5 with an option to disable hyperthreading in applications running untrusted code in a thread through a new sysctl. (CVE-2019-9815)
 - A possible vulnerability exists where type confusion can occur when manipulating JavaScript objects in object groups, allowing for the bypassing of security checks within these groups. Note: this vulnerability has only been demonstrated with UnboxedObjects, which are disabled by default on all supported releases. (CVE-2019-9816)
 - 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. (CVE-2019-9817)
 - A race condition is present in the crash generation server used to generate data for the crash reporter. This issue can lead to a use-after-free in the main process, resulting in a potentially exploitable crash and a sandbox escape. Note: this vulnerability only affects Windows. Other operating systems are unaffected. (CVE-2019-9818)
 - A vulnerability where a JavaScript compartment mismatch can occur while working with the fetch API, resulting in a potentially exploitable crash. (CVE-2019-9819)
 - A use-after-free vulnerability can occur in the chrome event handler when it is freed while still in use. This results in a potentially exploitable crash. (CVE-2019-9820)
 - A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash. (CVE-2019-9821)
 - 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. (CVE-2019-11691)
 - A use-after-free vulnerability can occur when listeners are removed from the event listener manager while still in use, resulting in a potentially exploitable crash. (CVE-2019-11692)
 - The bufferdata function in WebGL is vulnerable to a buffer overflow with specific graphics drivers on Linux. This could result in malicious content freezing a tab or triggering a potentially exploitable crash. Note: this issue only occurs on Linux. Other operating systems are unaffected. (CVE-2019-11693)
 - A use-after-free vulnerability was discovered in the png_image_free function in the libpng library. This could lead to denial of service or a potentially exploitable crash when a malformed image is processed. (CVE-2019-7317)
 - A vulnerability exists in the Windows sandbox where an uninitialized value in memory can be leaked to a renderer from a broker when making a call to access an otherwise unavailable file. This results in the potential leaking of information stored at that memory location. Note: this issue only occurs on Windows. Other operating systems are unaffected. (CVE-2019-11694)
 - 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. (CVE-2019-11695)
 - 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. (CVE-2019-11696)
 - 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. (CVE-2019-11697)
 - 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. (CVE-2019-11698)
 - 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. (CVE-2019-11700)
 - 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. (CVE-2019-11699)
 - 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. (CVE-2019-11701)
 - Mozilla developers and community members Christian Holler, Andrei Ciure, Julien Cristau, Jan de Mooij, Jan Varga, Marcia Knous, Andre Bargull, and Philipp reported memory safety bugs present in Firefox 66. 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. (CVE-2019-9814)
 - Mozilla developers and community members Olli Pettay, Bogdan Tara, Jan de Mooij, Jason Kratzer, Jan Varga, Gary Kwong, Tim Guan-tin Chien, Tyson Smith, Ronald Crane, and Ted Campbell reported memory safety bugs present in Firefox 66. 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. (CVE-2019-9800)

 Note that NNM has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
125809	openSUSE Security Update : MozillaFirefox (openSUSE-2019-1534)	Nessus	SuSE Local Security Checks	critical
125361	Mozilla Firefox < 67.0	Nessus	Windows	critical
125360	Mozilla Firefox < 67.0	Nessus	MacOS X Local Security Checks	critical
125346	FreeBSD : mozilla -- multiple vulnerabilities (44b6dfbf-4ef7-4d52-ad52-2b1b05d81272)	Nessus	FreeBSD Local Security Checks	critical
125339	Ubuntu 16.04 LTS / 18.04 LTS : Firefox vulnerabilities (USN-3991-1)	Nessus	Ubuntu Local Security Checks	critical
700727	Mozilla Firefox < 67.0 Multiple Vulnerabilities	Nessus Network Monitor	Web Clients	high

Detections

Analytics

CVE-2019-9821

high

Tenable Plugins

critical

critical

critical

critical

critical

high