CVE-2020-35111

Mozilla: The proxy.onRequest API did not catch view-source URLs

Severity Score

4.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

When an extension with the proxy permission registered to receive <all_urls>, the proxy.onRequest callback was not triggered for view-source URLs. While web content cannot navigate to such URLs, a user opening View Source could have inadvertently leaked their IP address. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Cuando una extensión con el permiso de proxy se registró para recibir (all_urls), la devolución de llamada proxy.onRequest no se desencadenó para las URL de vista de origen. Si bien el contenido web no puede navegar a dichas URL, un usuario que abra View Source podría haber filtrado inadvertidamente su dirección IP. Esta vulnerabilidad afecta a Firefox versiones anteriores a 84, Thunderbird versiones anteriores a 78,6 y Firefox ESR versiones anteriores a 78,6

The Mozilla Foundation Security Advisory describes this flaw as:

When an extension with the proxy permission registered to receive `<all_urls>`, the proxy.onRequest callback was not triggered for view-source URLs. While web content cannot navigate to such URLs, a user opening View Source could have inadvertently leaked their IP address.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

None

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-12-10 CVE Reserved
2020-12-16 CVE Published
2023-09-23 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

CAPEC

References (5)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2020-54	2021-01-12
https://www.mozilla.org/security/advisories/mfsa2020-55	2021-01-12
https://www.mozilla.org/security/advisories/mfsa2020-56	2021-01-12
https://access.redhat.com/security/cve/CVE-2020-35111	2020-12-21
https://bugzilla.redhat.com/show_bug.cgi?id=1908027	2020-12-21

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"				< 84.0 Search vendor "Mozilla" for product "Firefox" and version " < 84.0"		-		Affected
Mozilla Search vendor "Mozilla"		Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"				< 78.6.0 Search vendor "Mozilla" for product "Firefox Esr" and version " < 78.6.0"		-		Affected
Mozilla Search vendor "Mozilla"		Thunderbird Search vendor "Mozilla" for product "Thunderbird"				< 78.6.0 Search vendor "Mozilla" for product "Thunderbird" and version " < 78.6.0"		-		Affected