Mozilla Foundation Security Advisory 2020-12

Security Vulnerabilities fixed in Firefox 75

Announced April 7, 2020 Impact high Products Firefox Fixed in Firefox 75

# CVE-2020-6821: Uninitialized memory could be read when using the WebGL copyTexSubImage method Reporter Jeff Gilbert, Kenneth Russell Impact high Description When reading from areas partially or fully outside the source resource with WebGL's copyTexSubImage method, the specification requires the returned values be zero. Previously, this memory was uninitialized, leading to potentially sensitive data disclosure. References Bug 1625404

# CVE-2020-6822: Out of bounds write in GMPDecodeData when processing large images Reporter Deian Stefan Impact moderate Description On 32-bit builds, an out of bounds write could have occurred when processing an image larger than 4 GB in GMPDecodeData . It is possible that with enough effort this could have been exploited to run arbitrary code. References Bug 1544181

# CVE-2020-6823: Malicious Extension could obtain auth codes from OAuth login flows Reporter Leon Visscher Impact moderate Description A malicious extension could have called browser.identity.launchWebAuthFlow , controlling the redirect_uri, and through the Promise returned, obtain the Auth code and gain access to the user's account at the service provider. References Bug 1614919

# CVE-2020-6824: Generated passwords may be identical on the same site between separate private browsing sessions Reporter Matthew Noorenberghe Impact moderate Description Initially, a user opens a Private Browsing Window and generates a password for a site, then closes the Private Browsing Window but leaves Firefox open. Subsequently, if the user had opened a new Private Browsing Window, revisited the same site, and generated a new password - the generated passwords would have been identical, rather than independent. References Bug 1621853

# CVE-2020-6825: Memory safety bugs fixed in Firefox 75 and Firefox ESR 68.7 Reporter Mozilla developers Impact high Description Mozilla developers and community members Tyson Smith and Christian Holler reported memory safety bugs present in Firefox 74 and Firefox ESR 68.6. 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 75 and Firefox ESR 68.7