CVE-2021-29981

Ubuntu Security Notice USN-5248-1

Severity Score

8.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

An issue present in lowering/register allocation could have led to obscure but deterministic register confusion failures in JITted code that would lead to a potentially exploitable crash. This vulnerability affects Firefox < 91 and Thunderbird < 91.

Un problema presente en la asignación de bajada y registro podría haber conllevado a fallos de confusión de registro oscuros pero deterministas en el código JITted que conllevaría un bloqueo potencialmente explotable. Esta vulnerabilidad afecta a Firefox versiones anteriores a 91 y Thunderbird versiones anteriores a 91.

Multiple security issues were discovered in Thunderbird. If a user were tricked into opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, trick a user into accepting unwanted permissions, conduct header splitting attacks, conduct spoofing attacks, bypass security restrictions, confuse the user, or execute arbitrary code.

*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

2021-04-01 CVE Reserved
2021-08-17 CVE Published
2024-08-03 CVE Updated
2025-05-12 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (4)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://bugzilla.mozilla.org/show_bug.cgi?id=1707774	2022-03-16
https://security.gentoo.org/glsa/202202-03	2022-03-16
https://www.mozilla.org/security/advisories/mfsa2021-33	2022-03-16
https://www.mozilla.org/security/advisories/mfsa2021-36	2022-03-16

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"				< 91.0 Search vendor "Mozilla" for product "Firefox" and version " < 91.0"		-		Affected
Mozilla Search vendor "Mozilla"		Thunderbird Search vendor "Mozilla" for product "Thunderbird"				< 91.0 Search vendor "Mozilla" for product "Thunderbird" and version " < 91.0"		-		Affected