LiveActive security incident?Get immediate response
CVE Record

CVE-2021-41690: DCMTK through 3.6.6 does not handle memory free properly.

DCMTK through 3.6.6 does not handle memory free properly. The malloced memory for storing all file information are recorded in a global variable LST and are not freed properly. Sending specific requests to the dcmqrdb program can incur a memory leak. An attacker can use it to launch a DoS attack.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

DCMTK through 3.6.6 has a memory leak in dcmqrdb. A remote party sending certain requests could force the service to consume memory over time, creating a denial-of-service risk. The bundle does not provide a CVSS score or report active exploitation.

Executive priority

Prioritize patching where DCMTK supports clinical or imaging workflows and dcmqrdb is reachable beyond a tightly controlled host. The business risk is service interruption, especially in environments dependent on DICOM query and retrieve operations.

Technical view

The CVE describes malloced file-information records stored in global variable LST and not freed correctly. The affected component named in the description is dcmqrdb in DCMTK through 3.6.6. Impact is memory exhaustion and service disruption, not code execution based on the provided sources.

Likely exposure

Exposure is most likely where DCMTK through 3.6.6 is installed and dcmqrdb is reachable by users, partner networks, or the internet. Systems using vendor-packaged DCMTK may also be affected unless their package includes a backported fix.

Exploitation context

The source states that specific requests can trigger the leak and support a DoS attack. It does not cite public exploit code, observed exploitation, or CISA KEV inclusion. Treat internet-reachable dcmqrdb services as higher priority.

Researcher notes

Evidence is limited: no CVSS, CWE, CPE, or complete affected-product metadata is supplied. The key technical claim is an unreleased memory allocation path tied to global LST. The referenced upstream commit and Debian LTS notices should guide version-specific remediation analysis.

Mitigation direction

  • Apply DCMTK or operating-system vendor security updates for this CVE.
  • Review the referenced upstream commit and vendor advisories for fixed package status.
  • Restrict access to dcmqrdb to trusted networks and required peers.
  • Monitor dcmqrdb memory growth and service availability until patched.

Validation and detection

  • Inventory hosts running DCMTK and record exact package or source versions.
  • Confirm whether dcmqrdb is enabled and network reachable.
  • Check vendor package changelogs for CVE-2021-41690 backports.
  • Verify monitoring covers memory growth and restart events for affected services.
Prepared
Confidence
medium
Sources
6

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-41690 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
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
5Source 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.