CVE-2021-1771

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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
3.3 LOW
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
appleCNA
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CVEADP
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Base Score
CVSS 3.x
EPSS Score
Percentile: 47%
VendorProductVersion
applemac_os_x
10.14 ≤
𝑥
< 10.14.6
applemac_os_x
10.15 ≤
𝑥
< 10.15.7
applemac_os_x
10.14.6
applemac_os_x
10.14.6:security_update_2019-001
applemac_os_x
10.14.6:security_update_2019-002
applemac_os_x
10.14.6:security_update_2020-001
applemac_os_x
10.14.6:security_update_2020-002
applemac_os_x
10.14.6:security_update_2020-003
applemac_os_x
10.14.6:security_update_2020-004
applemac_os_x
10.14.6:security_update_2020-005
applemac_os_x
10.14.6:security_update_2020-006
applemac_os_x
10.14.6:security_update_2020-007
applemac_os_x
10.14.6:supplemental_update
applemac_os_x
10.14.6:supplemental_update_2
applemac_os_x
10.15.7
applemac_os_x
10.15.7:supplemental_update
applemacos
11.0 ≤
𝑥
< 11.2
𝑥
= Vulnerable software versions
References
https://support.apple.com/en-us/HT212147
https://support.apple.com/en-us/HT212147