CVE-2020-26973

Mozilla: CSS Sanitizer performed incorrect sanitization

Severity Score

8.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Certain input to the CSS Sanitizer confused it, resulting in incorrect components being removed. This could have been used as a sanitizer bypass. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Determinadas entradas hacia el CSS Sanitizer lo confundieron, resultando en una eliminación de componentes incorrectos. Esto podría haber sido usado como una omisión de saneo. 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:

Certain input to the CSS Sanitizer confused it, resulting in incorrect components being removed. This could have been used as a sanitizer bypass.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-10-12 CVE Reserved
2020-12-16 CVE Published
2024-08-04 CVE Updated
2024-11-11 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-20: Improper Input Validation

CAPEC

References (5)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2020-54	2021-01-11
https://www.mozilla.org/security/advisories/mfsa2020-55	2021-01-11
https://www.mozilla.org/security/advisories/mfsa2020-56	2021-01-11
https://access.redhat.com/security/cve/CVE-2020-26973	2020-12-21
https://bugzilla.redhat.com/show_bug.cgi?id=1908023	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