CVE-2021-4166: apple mac_os_x Out-of-bounds Read
CVSS: 7.1v3.0HighModified
AliasesALPINE-CVE-2021-4166UBUNTU-CVE-2021-4166DEBIAN-CVE-2021-4166
Published 25-12-2021Last modified 08-10-2026
Vulnerability summary
CVE-2021-4166 is a high (CVSS 7.1) Out-of-bounds Read vulnerability in apple mac_os_x. EPSS estimates a 1.70% chance of exploitation in the next 30 days, higher than 76.7% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
7.1/10
010
High · v3.0 (CVE.org)EPSS score
1.70%
0%100%
Low · +0.12 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference
Advisory lineage
Upstream 0 · Downstream 4 · Related 3Timeline
- 25-12-2021PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
vim is vulnerable to Out-of-bounds Read
CVSS metrics
8 scores · 5 sources · 3 versionsHigh 7.1Preferred score · OSV · Alpine (Ecosystem advisory) · calculated from vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:HSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
- NVDNIST7.1HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
High 7.1Preferred score · CVE.org (CNA)
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.1HighCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
- NVDNIST7.1HighCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Medium 5.8Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:P/I:N/A:PSourcesSingle source
EPSS trend
Probability
1.70%
Chance of exploitation in the next 30 days
Percentile
77%
Versus all other CVEs
30-day change
+0.12 pp
From 1.58% on 18-09-2026
18-09-202618-10-2026
EPSS score1.70%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (huntr.dev)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Apple2 products
- mac_os_x10.15.7 | 10.15.7:security_update_2020-001 | 10.15.7:security_update_2021-001 | 10.15.7:security_update_2021-002 | 10.15.7:security_update_2021-003 | 10.15.7:security_update_2021-004 | 10.15.7:security_update_2021-005 | 10.15.7:security_update_2021-006 | 10.15.7:security_update_2021-007 | 10.15.7:security_update_2021-008 | 10.15.7:security_update_2022-001 | 10.15.7:security_update_2022-002 | 10.15.7:security_update_2022-003
- macosEOL< 12.3 | ≥ 11.0, < 11.6.6 | 10.15.7:security_update_2022-004
Debian2 products
- vim< 2:8.2.3995-1
- debian_linuxEOL9.0 | 10.0 | 11.0
Alpine1 product
- vim< 8.2.4173-r0
Fedoraproject1 product
- fedoraEOL34 | 35
Opensuse1 product
- factoryna
Redhat1 product
Suse1 product
- linux_enterprise12.0 | 15.0
Ubuntu1 product
- vimAll versions (No fix recorded) | < 2:8.1.2269-1ubuntu5.14
9 vendors · 12 products
References
18 links- huntr.dev/bounties/229df5dd-5507-44e9-832c-c70364bdf035X Refsource CONFIRMExploitIssue TrackingPatchThird Party Advisory
- github.com/vim/vim/commit/6f98371532fcff911b462d51bc64f2ce8a6ae682X Refsource MISCPatchThird Party Advisory
