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CVE Record

CVE-2021-44732: Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an mbedtls_...

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Mbed TLS can double-free memory when setting an SSL session fails under certain out-of-memory conditions. This is a memory-safety bug in a TLS library, so impact depends on where embedded systems, applications, or packages use vulnerable Mbed TLS versions.

Executive priority

Treat as a dependency hygiene and embedded-product risk item. Prioritize confirmation in exposed services and shipped devices, but do not treat it as an emergency without evidence of exploitation or high-severity scoring.

Technical view

CVE-2021-44732 affects Mbed TLS before 3.0.1. The disclosed condition is a double free after an mbedtls_ssl_set_session() failure during memory exhaustion. The bundle does not provide CVSS, CWE, exploitability detail, or a complete affected product inventory.

Likely exposure

Exposure is most likely where software directly embeds Mbed TLS or relies on OS packages shipping vulnerable Mbed TLS versions. The provided affected-product metadata is incomplete, so inventory confirmation is required.

Exploitation context

The source bundle does not cite active exploitation, and KEV is false. The described trigger requires specific out-of-memory failure handling around SSL session setup, which suggests targeted reliability or memory-corruption risk rather than broad confirmed exploitation.

Researcher notes

Key gaps are missing CVSS, CWE, and affected CPE data. Validation should focus on library version provenance and whether vendor packages backported the fix, not only upstream version strings.

Mitigation direction

  • Upgrade Mbed TLS to 3.0.1 or a later vendor-supported fixed release.
  • Apply distribution security updates where Mbed TLS is supplied by the operating system.
  • Review ARM Mbed TLS release notes for maintained branch guidance.
  • Prioritize internet-facing TLS services and embedded products using Mbed TLS.

Validation and detection

  • Inventory applications, firmware, containers, and packages that include Mbed TLS.
  • Confirm deployed Mbed TLS versions are not before 3.0.1 unless vendor-fixed.
  • Check Debian or other distribution package changelogs for backported fixes.
  • Review TLS session-handling code paths that call mbedtls_ssl_set_session().
Prepared
Confidence
medium
Sources
10

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-44732 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
9Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.