CVE-2021-29988

Mozilla: Memory corruption as a result of incorrect style treatment

Severity Score

8.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Firefox incorrectly treated an inline list-item element as a block element, resulting in an out of bounds read or memory corruption, and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Firefox trataba incorrectamente un elemento de lista en línea como un elemento de bloqueo, resultando en una lectura fuera de límites o una corrupción de la memoria, y un bloqueo potencialmente explotable. Esta vulnerabilidad afecta a Thunderbird versiones anteriores a 78.13, Thunderbird versiones anteriores a 91, Firefox ESR versiones anteriores a 78.13 y Firefox versiones anteriores a 91.

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. This update upgrades Firefox to version 78.13.0 ESR. Issues addressed include a use-after-free vulnerability.

*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
2021-08-16 CVE Published
2024-08-03 CVE Updated
2024-08-03 First Exploit
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-125: Out-of-bounds Read
CWE-787: Out-of-bounds Write

CAPEC

References (9)

URL	Tag	Source

URL	Date	SRC
https://bugzilla.mozilla.org/show_bug.cgi?id=1717922	2024-08-03

URL	Date	SRC

URL	Date	SRC
https://security.gentoo.org/glsa/202202-03	2022-12-09
https://security.gentoo.org/glsa/202208-14	2022-12-09
https://www.mozilla.org/security/advisories/mfsa2021-33	2022-12-09
https://www.mozilla.org/security/advisories/mfsa2021-34	2022-12-09
https://www.mozilla.org/security/advisories/mfsa2021-35	2022-12-09
https://www.mozilla.org/security/advisories/mfsa2021-36	2022-12-09
https://access.redhat.com/security/cve/CVE-2021-29988	2021-08-16
https://bugzilla.redhat.com/show_bug.cgi?id=1992419	2021-08-16

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"		Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"				< 78.13.0 Search vendor "Mozilla" for product "Firefox Esr" and version " < 78.13.0"		-		Affected
Mozilla Search vendor "Mozilla"		Thunderbird Search vendor "Mozilla" for product "Thunderbird"				< 78.13.0 Search vendor "Mozilla" for product "Thunderbird" and version " < 78.13.0"		-		Affected