CVE-2020-12394: Security Vulnerabilities fixed in Firefox 76

Mozilla Foundation Security Advisory 2020-16

Announced

May 5, 2020

Impact

critical

Products

Firefox

Fixed in

• Firefox 76

#CVE-2020-12387: Use-after-free during worker shutdown

Reporter

Looben Yang

Impact

critical

Description

A race condition when running shutdown code for Web Worker led to a use-after-free vulnerability. This resulted in a potentially exploitable crash.

References

• Bug 1545345

#CVE-2020-12388: Sandbox escape with improperly guarded Access Tokens

Reporter

James Forshaw of Google Project Zero

Impact

critical

Description

The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape.
Note: this issue only affects Firefox on Windows operating systems.

References

• Bug 1618911

#CVE-2020-12389: Sandbox escape with improperly separated process types

Reporter

Niklas Baumstark

Impact

high

Description

The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape.
Note: this issue only affects Firefox on Windows operating systems.

References

• Bug 1554110

#CVE-2020-6831: Buffer overflow in SCTP chunk input validation

Reporter

Natalie Silvanovich of Google Project Zero

Impact

high

Description

A buffer overflow could occur when parsing and validating SCTP chunks in WebRTC. This could have led to memory corruption and a potentially exploitable crash.

References

• Bug 1632241

#CVE-2020-12390: Incorrect serialization of nsIPrincipal.origin for IPv6 addresses

Reporter

Giorgio Maone

Impact

moderate

Description

Incorrect origin serialization of URLs with IPv6 addresses could lead to incorrect security checks

References

• Bug 1141959

#CVE-2020-12391: Content-Security-Policy bypass using object elements

Reporter

Giorgio Maone

Impact

moderate

Description

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.

References

• Bug 1457100

#CVE-2020-12392: Arbitrary local file access with ‘Copy as cURL’

Reporter

Ophir LOJKINE

Impact

moderate

Description

The ‘Copy as cURL’ feature of Devtools’ network tab did not properly escape the HTTP POST data of a request, which can be controlled by the website. If a user used the ‘Copy as cURL’ feature and pasted the command into a terminal, it could have resulted in the disclosure of local files.

References

• Bug 1614468

#CVE-2020-12393: Devtools’ ‘Copy as cURL’ feature did not fully escape website-controlled data, potentially leading to command injection

Reporter

David Yesland

Impact

moderate

Description

The ‘Copy as cURL’ feature of Devtools’ network tab did not properly escape the HTTP method of a request, which can be controlled by the website. If a user used the ‘Copy as cURL’ feature and pasted the command into a terminal, it could have resulted in command injection and arbitrary command execution.
Note: this issue only affects Firefox on Windows operating systems.

References

• Bug 1615471

#CVE-2020-12394: URL spoofing in location bar when unfocussed

Reporter

Kestrel

Impact

low

Description

A logic flaw in our location bar implementation could have allowed a local attacker to spoof the current location by selecting a different origin and removing focus from the input element.

References

• Bug 1628288

#CVE-2020-12395: Memory safety bugs fixed in Firefox 76 and Firefox ESR 68.8

Reporter

Mozilla developers and community

Impact

critical

Description

Mozilla developers and community members Alexandru Michis, Jason Kratzer, philipp, Ted Campbell, Bas Schouten, André Bargull, and Karl Tomlinson reported memory safety bugs present in Firefox 75 and Firefox ESR 68.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.

References

• Memory safety bugs fixed in Firefox 76 and Firefox ESR 68.8

#CVE-2020-12396: Memory safety bugs fixed in Firefox 76

Reporter

Mozilla developers and community

Impact

high

Description

Mozilla developers and community members Frederik Braun, Andrew McCreight, C.M.Chang, and Dan Minor reported memory safety bugs present in Firefox 75. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.

References

• Memory safety bugs fixed in Firefox 76