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.
Conclusion & alert: CVE-2021-41690 is rated Low Risk (39.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.10%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2025-11-21 | 0.51% | 0.10% | -0.42% |
| 2 | 2025-11-18 | 0.07% | 0.51% | +0.44% |
| 3 | 2025-03-30 | — | 0.07% | — |
Full EPSS history (9 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2021-41690 not yet assigned priority: Debian including 1 source packages (dcmtk), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2021-41690 |
ubuntu
|
low | CVE-2021-41690 low priority: Ubuntu including 1 source packages (dcmtk), 14 status rows across 14 suites (bionic, focal, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 7, released 5, DNE 1, ignored 1. | https://ubuntu.com/security/CVE-2021-41690 |
| URL | Tags |
|---|---|
| https://github.com/DCMTK/dcmtk | Product Third Party Advisory |
| https://github.com/DCMTK/dcmtk/commit/a9697dfeb672b0b9412c00c7d36d801e27ec85cb | Patch Third Party Advisory |
| https://lists.debian.org/debian-lts-announce/2024/06/msg00022.html | |
| https://lists.debian.org/debian-lts-announce/2025/01/msg00032.html |