Vulnerability CVE-2021-1771

Vulnerability Name:

CVE-2021-1771 (CCN-195912)

Assigned:

2020-12-08

Published:

2021-02-01

Updated:

2021-04-12

Summary:

This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. A user that is removed from an iMessage group could rejoin the group.

CVSS v3 Severity:

3.3 Low (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N)
2.9 Low (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C)

Exploitability Metrics:	Attack Vector (AV): Local Attack Complexity (AC): Low Privileges Required (PR): None User Interaction (UI): Required
Scope:	Scope (S): Unchanged
Impact Metrics:	Confidentiality (C): None Integrity (I): Low Availibility (A): None

5.5 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N)
4.8 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)

Exploitability Metrics:	Attack Vector (AV): Local Attack Complexity (AC): Low Privileges Required (PR): None User Interaction (UI): Required
Scope:	Scope (S): Unchanged
Impact Metrics:	Confidentiality (C): None Integrity (I): High Availibility (A): None

CVSS v2 Severity:

4.3 Medium (CVSS v2 Vector: AV:N/AC:M/Au:N/C:N/I:P/A:N)

Exploitability Metrics:	Access Vector (AV): Network Access Complexity (AC): Medium Authentication (Au): None
Impact Metrics:	Confidentiality (C): None Integrity (I): Partial Availibility (A): None

4.6 Medium (CCN CVSS v2 Vector: AV:L/AC:L/Au:S/C:N/I:C/A:N)

Exploitability Metrics:	Access Vector (AV): Local Access Complexity (AC): Low Athentication (Au): Single_Instance
Impact Metrics:	Confidentiality (C): None Integrity (I): Complete Availibility (A): None