CVE-2021-43666: arm mbed_tls
CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2021-43666DEBIAN-CVE-2021-43666
Published 24-03-2022Last modified 02-12-2025
Vulnerability summary
CVE-2021-43666 is a high (CVSS 7.5) vulnerability in arm mbed_tls. EPSS estimates a 2.07% chance of exploitation in the next 30 days, higher than 81.1% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
2.07%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github
Advisory lineage
Upstream 0 · Downstream 2Timeline
- 24-03-2022PublishedVulnerability first disclosed.
- 02-12-2025Last modifiedVulnerability information updated.
Description
A Denial of Service vulnerability exists in mbed TLS 3.0.0 and earlier in the mbedtls_pkcs12_derivation function when an input password's length is 0.
CVSS metrics
5 scores · 4 sources · 2 versionsHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Medium 5.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:N/I:N/A:PSourcesSingle source
EPSS trend
Probability
2.07%
Chance of exploitation in the next 30 days
Percentile
81%
Versus all other CVEs
30-day change
0.00 pp
From 2.07% on 19-09-2026
19-09-202619-10-2026
EPSS score2.07%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundMbedtls
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Debian2 products
- mbedtls< 2.28.0-1
- debian_linuxEOL10.0
Arm1 product
- mbed_tls≤ 3.0.0
Ubuntu1 product
- mbedtlsAll versions (No fix recorded)
3 vendors · 4 products
