CVE-2021-29989

Mozilla: Memory safety bugs fixed in Thunderbird 78.13

Severity Score

8.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Mozilla developers reported memory safety bugs present in Firefox 90 and Firefox ESR 78.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 78.13, Firefox ESR < 78.13, and Firefox < 91.

Los desarrolladores de Mozilla informaron de bugs de seguridad de memoria presentes en Firefox 90 y Firefox ESR 78.12. Algunos de estos bugs mostraron evidencias de corrupción de la memoria y presumimos que con esfuerzo suficiente algunos de ellos podrían haber sido explotados para ejecutar código arbitrario. Esta vulnerabilidad afecta a Thunderbird versiones anteriores a 78.13, Firefox ESR versiones anteriores a 78.13 y Firefox versiones anteriores a 91.

It was discovered that Thunderbird didn't ignore IMAP server responses prior to completion of the STARTTLS handshake. A person-in-the-middle could potentially exploit this to trick Thunderbird into showing incorrect information. 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, or execute arbitrary code. Various other issues were also addressed.

*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
2021-08-12 CVE Published
2024-08-03 CVE Updated
2025-06-08 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-787: Out-of-bounds Write

CAPEC

References (8)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1662676%2C1666184%2C1719178%2C1719998%2C1720568	2022-12-09
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://access.redhat.com/security/cve/CVE-2021-29989	2021-08-16
https://bugzilla.redhat.com/show_bug.cgi?id=1992423	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