CVE-2021-4136: apple mac_os_x Heap-based Buffer Overflow
CVSS: 7.8v3.1HighModified
AliasesALPINE-CVE-2021-4136UBUNTU-CVE-2021-4136DEBIAN-CVE-2021-4136
Published 19-12-2021Last modified 08-10-2026
Vulnerability summary
CVE-2021-4136 is a high (CVSS 7.8) Heap-based Buffer Overflow vulnerability in apple mac_os_x. EPSS estimates a 1.97% chance of exploitation in the next 30 days, higher than 80% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
7.8/10
010
High · v3.1 (NVD)EPSS score
1.97%
0%100%
Low · +0.14 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference
Advisory lineage
Upstream 0 · Downstream 3 · Related 2Timeline
- 19-12-2021PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
vim is vulnerable to Heap-based Buffer Overflow
CVSS metrics
8 scores · 5 sources · 3 versionsHigh 7.8Preferred score · NVD (NIST)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSourcesAll 4 agree
- OSV · AlpineEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
High 7.3Preferred score · CVE.org (CNA)
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:LSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.3HighCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L
- NVDNIST7.3HighCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L
Medium 6.8Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
1.97%
Chance of exploitation in the next 30 days
Percentile
80%
Versus all other CVEs
30-day change
+0.14 pp
From 1.83% on 18-09-2026
18-09-202618-10-2026
EPSS score1.97%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (huntr.dev)
Maturity: unknown
Weaknesses
CWE · root cause- CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Apple2 products
- mac_os_x≥ 10.15, < 10.15.7 | 10.15.7 | 10.15.7:security_update_2020 | 10.15.7:security_update_2020-001 | 10.15.7:security_update_2020-005 | 10.15.7:security_update_2020-007 | 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_2021-006 | 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 | 10.15.7:security_update_2022-004 | 10.15.7:supplemental_update
- macos≥ 11.0, < 11.6.6 | ≥ 12.0, < 12.3
Alpine1 product
- vim< 8.2.4173-r0
Debian1 product
- vim< 2:8.2.3995-1
Fedoraproject1 product
- fedoraEOL34 | 35
Ubuntu1 product
- vim< 2:8.2.3995-1ubuntu2
6 vendors · 8 products
References
17 links- huntr.dev/bounties/5c6b93c1-2d27-4e98-a931-147877b8c938X Refsource CONFIRMREPORTExploitPatchThird Party Advisory
- github.com/vim/vim/commit/605ec91e5a7330d61be313637e495fa02a6dc264X Refsource MISCREPORTPatchThird Party Advisory
