CVE-2021-3973: debian debian_linux Heap-based Buffer Overflow
CVSS: 9.3v2.0HighModified
AliasesALPINE-CVE-2021-3973UBUNTU-CVE-2021-3973DEBIAN-CVE-2021-3973
Published 19-11-2021Last modified 08-10-2026
Vulnerability summary
CVE-2021-3973 is a high (CVSS 9.3) Heap-based Buffer Overflow vulnerability in debian debian_linux. EPSS estimates a 1.79% chance of exploitation in the next 30 days, higher than 77.9% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
9.3/10
010
High · v2.0 (NVD)EPSS score
1.79%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference
Advisory lineage
Upstream 0 · Downstream 7 · Related 5Timeline
- 19-11-2021PublishedVulnerability 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 · OSV · Alpine (Ecosystem advisory) · calculated from vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSourcesAll 4 agree
- 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
- NVDNIST7.8HighCVSS: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:L/I:H/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.3HighCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H
- NVDNIST7.3HighCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H
High 9.3Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:C/I:C/A:CSourcesSingle source
EPSS trend
Probability
1.79%
Chance of exploitation in the next 30 days
Percentile
78%
Versus all other CVEs
30-day change
0.00 pp
From 1.79% on 18-09-2026
18-09-202618-10-2026
EPSS score1.79%
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
Debian2 products
- vim< 2:8.2.3995-1
- debian_linuxEOL9.0
Alpine1 product
- vim< 8.2.3650-r0
Fedoraproject1 product
- fedoraEOL34 | 35
Ubuntu1 product
- vim< 2:7.4.052-1ubuntu3.1+esm17 | < 2:7.4.1689-3ubuntu1.5+esm4 | < 2:8.0.1453-1ubuntu1.8 | < 2:8.1.2269-1ubuntu5.6
5 vendors · 7 products
References
15 links- huntr.dev/bounties/ce6e8609-77c6-4e17-b9fc-a2e5abed052eX Refsource CONFIRMExploitIssue TrackingPatchThird Party Advisory
- github.com/vim/vim/commit/615ddd5342b50a6878a907062aa471740bd9a847X Refsource MISCPatchThird Party Advisory
lists.debian.org/debian-lts-announce/2022/03/msg00018.htmlMailing ListX Refsource MLISTThird Party Advisory
