CVE-2021-44732: arm mbed_tls Double Free
CVSS: 9.8v3.1CriticalModified
AliasesALPINE-CVE-2021-44732MGASA-2022-0017UBUNTU-CVE-2021-44732DEBIAN-CVE-2021-44732
Published 20-12-2021Last modified 03-11-2025
Vulnerability summary
CVE-2021-44732 is a critical (CVSS 9.8) Double Free vulnerability in arm mbed_tls. EPSS estimates a 2.77% chance of exploitation in the next 30 days, higher than 86.1% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
9.8/10
010
Critical · v3.1 (NVD)EPSS score
2.77%
0%100%
Low · +0.19 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference
Advisory lineage
Upstream 0 · Downstream 3 · Related 1Timeline
- 20-12-2021PublishedVulnerability first disclosed.
- 03-11-2025Last modifiedVulnerability information updated.
Description
Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an mbedtls_ssl_set_session() failure.
CVSS metrics
5 scores · 4 sources · 2 versionsCritical 9.8Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSourcesAll 4 agree
- OSV · AlpineEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
High 7.5Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
2.77%
Chance of exploitation in the next 30 days
Percentile
86%
Versus all other CVEs
30-day change
+0.19 pp
From 2.58% on 19-09-2026
19-09-202619-10-2026
EPSS score2.77%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (tls.mbed.org)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Debian2 products
- mbedtls< 2.28.0-0.3
- debian_linuxEOL10.0
Alpine1 product
- mbedtls< 2.16.12-r0
Arm1 product
- mbed_tls< 2.16.12 | ≥ 2.17.0, < 2.28.0
Mageia1 product
- mbedtls< 2.16.12-1.mga8
Trustedfirmware1 product
- mbed_tls3.0.0 | 3.0.0:preview1
Ubuntu1 product
- mbedtlsAll versions (No fix recorded) | < 2.8.0-1ubuntu0.1~esm1 | < 2.16.4-1ubuntu2+esm1
6 vendors · 7 products
References
15 links- tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-12AdvisoryREPORTExploitMitigationThird Party Advisory
