Mozilla Foundation Security Advisory 2017-18

Security vulnerabilities fixed in Firefox 55

Announced
August 8, 2017
Impact
critical
Products
Firefox
Fixed in
  • Firefox 55

#CVE-2017-7798: XUL injection in the style editor in devtools

Reporter
Frederik Braun
Impact
critical
Description

The Developer Tools feature suffers from a XUL injection vulnerability due to improper sanitization of the web page source code. In the worst case, this could allow arbitrary code execution when opening a malicious page with the style editor tool.

References

#CVE-2017-7800: Use-after-free in WebSockets during disconnection

Reporter
Looben Yang
Impact
critical
Description

A use-after-free vulnerability can occur in WebSockets when the object holding the connection is freed before the disconnection operation is finished. This results in an exploitable crash.

References

#CVE-2017-7801: Use-after-free with marquee during window resizing

Reporter
Nils
Impact
critical
Description

A use-after-free vulnerability can occur while re-computing layout for a marquee element during window resizing where the updated style object is freed while still in use. This results in a potentially exploitable crash.

References

#CVE-2017-7809: Use-after-free while deleting attached editor DOM node

Reporter
Nils
Impact
high
Description

A use-after-free vulnerability can occur when an editor DOM node is deleted prematurely during tree traversal while still bound to the document. This results in a potentially exploitable crash.

References

#CVE-2017-7784: Use-after-free with image observers

Reporter
Nils
Impact
high
Description

A use-after-free vulnerability can occur when reading an image observer during frame reconstruction after the observer has been freed. This results in a potentially exploitable crash.

References

#CVE-2017-7802: Use-after-free resizing image elements

Reporter
Nils
Impact
high
Description

A use-after-free vulnerability can occur when manipulating the DOM during the resize event of an image element. If these elements have been freed due to a lack of strong references, a potentially exploitable crash may occur when the freed elements are accessed.

References

#CVE-2017-7785: Buffer overflow manipulating ARIA attributes in DOM

Reporter
Nils
Impact
high
Description

A buffer overflow can occur when manipulating Accessible Rich Internet Applications (ARIA) attributes within the DOM. This results in a potentially exploitable crash.

References

#CVE-2017-7786: Buffer overflow while painting non-displayable SVG

Reporter
Nils
Impact
high
Description

A buffer overflow can occur when the image renderer attempts to paint non-displayable SVG elements. This results in a potentially exploitable crash.

References

#CVE-2017-7806: Use-after-free in layer manager with SVG

Reporter
Nils
Impact
high
Description

A use-after-free vulnerability can occur when the layer manager is freed too early when rendering specific SVG content, resulting in a potentially exploitable crash.

References

#CVE-2017-7753: Out-of-bounds read with cached style data and pseudo-elements

Reporter
SkyLined
Impact
high
Description

An out-of-bounds read occurs when applying style rules to pseudo-elements, such as ::first-line, using cached style data.

References

#CVE-2017-7787: Same-origin policy bypass with iframes through page reloads

Reporter
Oliver Wagner
Impact
high
Description

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.

References

#CVE-2017-7807: Domain hijacking through AppCache fallback

Reporter
Mathias Karlsson
Impact
high
Description

A mechanism that uses AppCache to hijack a URL in a domain using fallback by serving the files from a sub-path on the domain. This has been addressed by requiring fallback files be inside the manifest directory.

References

#CVE-2017-7792: Buffer overflow viewing certificates with an extremely long OID

Reporter
Fraser Tweedale
Impact
high
Description

A buffer overflow will occur when viewing a certificate in the certificate manager if the certificate has an extremely long object identifier (OID). This results in a potentially exploitable crash.

References

#CVE-2017-7804: Memory protection bypass through WindowsDllDetourPatcher

Reporter
Stephen Fewer
Impact
high
Description

The destructor function for the WindowsDllDetourPatcher class can be re-purposed by malicious code in concert with another vulnerability to write arbitrary data to an attacker controlled location in memory. This can be used to bypass existing memory protections in this situation.
Note: This attack only affects Windows operating systems. Other operating systems are not affected.

References

#CVE-2017-7791: Spoofing following page navigation with data: protocol and modal alerts

Reporter
Jose María Acuña
Impact
moderate
Description

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.

References

#CVE-2017-7808: CSP information leak with frame-ancestors containing paths

Reporter
Jun Kokatsu
Impact
moderate
Description

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.

References

#CVE-2017-7782: WindowsDllDetourPatcher allocates memory without DEP protections

Reporter
Arthur Edelstein
Impact
moderate
Description

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.

References

#CVE-2017-7781: Elliptic curve point addition error when using mixed Jacobian-affine coordinates

Reporter
Antonio Sanso
Impact
moderate
Description

An error occurs in the elliptic curve point addition algorithm that uses mixed Jacobian-affine coordinates where it can yield a result POINT_AT_INFINITY when it should not. A man-in-the-middle attacker could use this to interfere with a connection, resulting in an attacked party computing an incorrect shared secret.

References

#CVE-2017-7794: Linux file truncation via sandbox broker

Reporter
Jann Horn
Impact
moderate
Description

On Linux systems, if the content process is compromised, the sandbox broker will allow files to be truncated even though the sandbox explicitly only has read access to the local file system and no write permissions.
Note: This attack only affects the Linux operating system. Other operating systems are not affected.

References

#CVE-2017-7803: CSP containing 'sandbox' improperly applied

Reporter
Rhys Enniks
Impact
moderate
Description

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.

References

#CVE-2017-7799: Self-XSS XUL injection in about:webrtc

Reporter
Frederik Braun
Impact
moderate
Description

JavaScript in the about:webrtc page is not sanitized properly being assigned to innerHTML. Data on this page is supplied by WebRTC usage and is not under third-party control, making this difficult to exploit, but the vulnerability could possibly be used for a cross-site scripting (XSS) attack.

References

#CVE-2017-7783: DOS attack through long username in URL

Reporter
Amit Sangra
Impact
low
Description

If a long user name is used in a username/password combination in a site URL (such as http://UserName:Password@example.com), the resulting modal prompt will hang in a non-responsive state or crash, causing a denial of service.

References

#CVE-2017-7788: Sandboxed about:srcdoc iframes do not inherit CSP directives

Reporter
Muneaki Nishimura
Impact
low
Description

When an iframe has a sandbox attribute and its content is specified using srcdoc, that content does not inherit the containing page's Content Security Policy (CSP) as it should unless the sandbox attribute included allow-same-origin.

References

#CVE-2017-7789: Failure to enable HSTS when two STS headers are sent for a connection

Reporter
Muneaki Nishimura
Impact
low
Description

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.

References

#CVE-2017-7790: Windows crash reporter reads extra memory for some non-null-terminated registry values

Reporter
Xiaoyin Liu
Impact
low
Description

On Windows systems, if non-null-terminated strings are copied into the crash reporter for some specific registry keys, stack memory data can be copied until a null is found. This can potentially contain private data from the local system.
Note: This attack only affects Windows operating systems. Other operating systems are not affected.

References

#CVE-2017-7796: Windows updater can delete any file named update.log

Reporter
Matt Howell
Impact
low
Description

On Windows systems, the logger run by the Windows updater deletes the file "update.log" before it runs in order to write a new log of that name. The path to this file is supplied at the command line to the updater and could be used in concert with another local exploit to delete a different file named "update.log" instead of the one intended.
Note: This attack only affects Windows operating systems. Other operating systems are not affected.

References

#CVE-2017-7797: Response header name interning leaks across origins

Reporter
Anne van Kesteren
Impact
low
Description

Response header name interning does not have same-origin protections and these headers are stored in a global registry. This allows stored header names to be available cross-origin.

References

#CVE-2017-7780: Memory safety bugs fixed in Firefox 55

Reporter
Mozilla developers and community
Impact
critical
Description

Mozilla developers and community members Gary Kwong, Christian Holler, André Bargull, Bob Clary, Carsten Book, Emilio Cobos Álvarez, Masayuki Nakano, Sebastian Hengst, Franziskus Kiefer, Tyson Smith, and Ronald Crane reported memory safety bugs present in Firefox 54. 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.

References

#CVE-2017-7779: Memory safety bugs fixed in Firefox 55 and Firefox ESR 52.3

Reporter
Mozilla developers and community
Impact
critical
Description

Mozilla developers and community members Masayuki Nakano, Gary Kwong, Ronald Crane, Andrew McCreight, Tyson Smith, Bevis Tseng, Christian Holler, Bryce Van Dyk, Dragana Damjanovic, Kartikaya Gupta, Philipp, Tristan Bourvon, and Andi-Bogdan Postelnicu reported memory safety bugs present in Firefox 54 and Firefox ESR 52.2. 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.

References