CVE-2020-6819, CVE-2020-6820: Critical Mozilla Firefox Zero-Day Vulnerabilities Exploited in the Wild
Researchers report multiple zero-day vulnerabilities in Mozilla Firefox and note that other browsers are also affected.
Antecedentes
On April 3, Mozilla Foundation published advisory 2020-11 for Mozilla Firefox and Mozilla Firefox Extended Support Release (ESR). The advisory includes fixes for two critical zero-day vulnerabilities, both of which were exploited in the wild as part of targeted attacks.
The discovery of these vulnerabilities was credited to security researchers Francisco Alonso and Javier Marcos. Alonso tweeted there are “more details to be published (including other browsers),” indicating these flaws likely extend to other web browsers. However, that information is currently not public, likely an effort to keep the details private until patches are available.
There is still lots of work to do and more details to be published (including other browsers). Stay tuned.
— Francisco Alonso (@revskills) April 3, 2020
As we’ve seen time and again, attackers continue to target widely installed applications such as web browsers. These latest vulnerabilities follow on the heels of another zero-day vulnerability in Mozilla Firefox exploited in the wild in January 2020.
Análisis
CVE-2020-6819 is a use-after-free vulnerability due to a race condition when the nsDocShell destructor is running. Based on the GitHub commit history for the nsDocShell.cpp file, it appears the issue exists due to the mContentViewer not being released properly.
Image source: GitHub of nsDocShell changes made to address CVE-2020-6819
CVE-2020-6820 is a use-after-free vulnerability due to a race condition in the ReadableStream class, which is used to read a stream of data.
Image source: MDN web docs
We anticipate further details about these vulnerabilities will be publicly available once the researchers publish their findings.
Prueba de concepto
At the time this blog post was published, there was no proof-of-concept code available for either of these vulnerabilities.
Solución
Mozilla Foundation released Mozilla Firefox 74.0.1 and Mozilla Firefox ESR 68.6.1 to address these vulnerabilities. While these vulnerabilities were exploited in targeted attacks, Firefox users are still encouraged to upgrade as soon as possible.
Identificación de los sistemas afectados
A list of Tenable plugins to identify these vulnerabilities will appear here as they’re released.
Obtenga más información
Únase al Equipo de respuesta de seguridad de Tenable en Tenable Community.
Obtenga más información sobre Tenable, la primera plataforma de Cyber Exposure para el control integral de la superficie de ataque moderna.
Obtenga una prueba gratuita por 30 días de Tenable.io Vulnerability Management.
Artículos relacionados
CVE-2024-47575: Frequently Asked Questions About FortiJump Zero-Day in FortiManager and FortiManager Cloud
October 23, 2024Frequently asked questions about a zero-day vulnerability in Fortinet’s FortiManager that has reportedly been exploited in the wild.
From Bugs to Breaches: 25 Significant CVEs As MITRE CVE Turns 25
October 22, 2024Twenty five years after the launch of CVE, the Tenable Security Response Team has handpicked 25 vulnerabilities that stand out for their significance.
Oracle October 2024 Critical Patch Update Addresses 198 CVEs
October 15, 2024Oracle addresses 198 CVEs in its fourth quarterly update of 2024 with 334 patches, including 35 critical updates.
Cybersecurity Snapshot: Apply Zero Trust to Critical Infrastructure’s OT/ICS, CSA Advises, as Five Eyes Spotlight Tech Startups’ Security
November 1, 2024Should critical infrastructure orgs boost OT/ICS systems’ security with zero trust? Absolutely, the CSA says. Meanwhile, the Five Eyes countries offer cyber advice to tech startups. Plus, a survey finds “shadow AI” weakening data governance. And get the latest on MFA methods, CISO trends and Uncle Sam’s AI strategy.
FY 2024 State and Local Cybersecurity Grant Program Adds CISA KEV as a Performance Measure
October 31, 2024The CISA Known Exploited Vulnerabilities (KEV) catalog and enhanced logging guidelines are among the new measurement tools added for the 2024 State and Local Cybersecurity Grant Program.
Cybersecurity Snapshot: New Guides Offer Best Practices for Preventing Shadow AI and for Deploying Secure Software Updates
October 25, 2024Looking for help with shadow AI? Want to boost your software updates’ safety? New publications offer valuable tips. Plus, learn why GenAI and data security have become top drivers of cyber strategies. And get the latest on the top “no-nos” for software security; the EU’s new cyber law; and CISOs’ communications with boards.
- Vulnerability Management