CVE-2020-26961

Mozilla: DoH did not filter IPv4 mapped IP Addresses

Severity Score

6.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses as these do not make sense coming from a DoH resolver. However when an IPv4 address was mapped through IPv6, these addresses were erroneously let through, leading to a potential DNS Rebinding attack. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Cuando un DNS sobre HTTPS está en uso, intencionalmente filtra el RFC1918 y los rangos de IP relacionados con las respuestas, ya que no tiene sentido al venir de un resolutor de DoH. Sin embargo, cuando una dirección IPv4 fue mapeada por medio de IPv6, estas direcciones fueron dejadas pasar erróneamente, conllevando a un potencial ataque de DNS Rebinding. Esta vulnerabilidad afecta a Firefox versiones anteriores a 83, Firefox ESR versiones anteriores a 78,5 y Thunderbird versiones anteriores a 78,5

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-10-12 CVE Reserved
2020-11-18 CVE Published
2024-08-04 CVE Updated
2024-10-13 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-358: Improperly Implemented Security Check for Standard

CAPEC

References (5)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2020-50	2020-12-10
https://www.mozilla.org/security/advisories/mfsa2020-51	2020-12-10
https://www.mozilla.org/security/advisories/mfsa2020-52	2020-12-10
https://access.redhat.com/security/cve/CVE-2020-26961	2020-12-01
https://bugzilla.redhat.com/show_bug.cgi?id=1898738	2020-12-01

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"				< 83.0 Search vendor "Mozilla" for product "Firefox" and version " < 83.0"		-		Affected
Mozilla Search vendor "Mozilla"		Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"				< 78.5 Search vendor "Mozilla" for product "Firefox Esr" and version " < 78.5"		-		Affected
Mozilla Search vendor "Mozilla"		Thunderbird Search vendor "Mozilla" for product "Thunderbird"				< 78.5 Search vendor "Mozilla" for product "Thunderbird" and version " < 78.5"		-		Affected