CVE-2019-9812

Mozilla Firefox sync Universal Cross-Site Scripting Sandbox Escape Vulnerability

Severity Score

9.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Given a compromised sandboxed content process due to a separate vulnerability, it is possible to escape that sandbox by loading accounts.firefox.com in that process and forcing a log-in to a malicious Firefox Sync account. Preference settings that disable the sandbox are then synchronized to the local machine and the compromised browser would restart without the sandbox if a crash is triggered. This vulnerability affects Firefox ESR < 60.9, Firefox ESR < 68.1, and Firefox < 69.

Dado un proceso de contenido comprometido dentro del sandbox debido a una vulnerabilidad separada, es posible escapar de ese sandbox cargando accounts.firefox.com en ese proceso y forzando un inicio de sesión en una cuenta de Firefox Sync maliciosa. La configuración de preferencias que deshabilita el sandbox es sincronizada con la máquina local y el navegador comprometido se reiniciará sin el sandbox si es activado un bloqueo. Esta vulnerabilidad afecta a Firefox ESR versiones anteriores a 60.9, Firefox ESR versiones anteriores a la versión 68.1 y Firefox versiones anteriores a la versión 69.

This vulnerability allows remote attackers to escape the sandbox on affected installations of Mozilla Firefox. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists due to a universal cross-site scripting issue when syncing accounts. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the current user at medium integrity.

*Credits: Niklas Baumstark (@_niklasb)

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

None

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

Low

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2019-03-14 CVE Reserved
2019-09-04 CVE Published
2024-01-15 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-250: Execution with Unnecessary Privileges

CAPEC

References (5)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2019-25	2021-07-21
https://www.mozilla.org/security/advisories/mfsa2019-26	2021-07-21
https://www.mozilla.org/security/advisories/mfsa2019-27	2021-07-21
https://access.redhat.com/security/cve/CVE-2019-9812	2019-09-12
https://bugzilla.redhat.com/show_bug.cgi?id=1748660	2019-09-12

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Mozilla Search vendor "Mozilla"		Firefox Search vendor "Mozilla" for product "Firefox"				< 69.0 Search vendor "Mozilla" for product "Firefox" and version " < 69.0"		-		Affected
Mozilla Search vendor "Mozilla"		Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"				< 60.9 Search vendor "Mozilla" for product "Firefox Esr" and version " < 60.9"		-		Affected
Mozilla Search vendor "Mozilla"		Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"				>= 61.0 < 68.1 Search vendor "Mozilla" for product "Firefox Esr" and version " >= 61.0 < 68.1"		-		Affected