# CVE-2021-41689: dcmtk: DCMTK through 3.6.6 does not handle string copy properly

CVE-2021-41689 is fixed in 4 products on 1 platform, first by DEBIAN-CVE-2021-41689, released June 28, 2022. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-41689
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0195
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 28, 2022

## Description

DCMTK through 3.6.6 does not handle string copy properly. Sending specific requests to the dcmqrdb program, it would query its database and copy the result even if the result is null, which can incur a head-based overflow. An attacker can use it to launch a DoS attack.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dcmtk Debian 12.15 (bookworm) | 3.6.7-1 | [DEBIAN-CVE-2021-41689](https://patchblox.com/security/data/fix/linux/debian-cve-2021-41689.md) | Jun 28, 2022 |
| Linux | dcmtk Debian 13.5 (trixie) | 3.6.7-1 | [DEBIAN-CVE-2021-41689](https://patchblox.com/security/data/fix/linux/debian-cve-2021-41689.md) | Jun 28, 2022 |
| Linux | dcmtk Debian 14 | 3.6.7-1 | [DEBIAN-CVE-2021-41689](https://patchblox.com/security/data/fix/linux/debian-cve-2021-41689.md) | Jun 28, 2022 |
| Linux | dcmtk Ubuntu 18.04.6 LTS (bionic) | 3.6.2-3ubuntu0.1~esm1 | [dcmtk 3.6.2-3ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dcmtk-3.6.2-3ubuntu0.1-esm1.md) | Dec 2, 2022 |
| Linux | dcmtk Ubuntu 20.04 LTS (focal) | 3.6.4-2.1ubuntu0.1~esm1 | [dcmtk 3.6.4-2.1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dcmtk-3.6.4-2.1ubuntu0.1-esm1.md) | Dec 2, 2022 |
| Linux | dcmtk Ubuntu 22.04.1 LTS (jammy) | 3.6.6-5ubuntu0.1~esm1 | [dcmtk 3.6.6-5ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-dcmtk-3.6.6-5ubuntu0.1-esm1.md) | Dec 2, 2022 |
| Linux | libdcmtk12 Ubuntu 18.04.6 LTS (bionic) | 3.6.2-3ubuntu0.1~esm1 | [libdcmtk12 3.6.2-3ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libdcmtk12-3.6.2-3ubuntu0.1-esm1.md) | Dec 2, 2022 |
| Linux | libdcmtk14 Ubuntu 20.04 LTS (focal) | 3.6.4-2.1ubuntu0.1~esm1 | [libdcmtk14 3.6.4-2.1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libdcmtk14-3.6.4-2.1ubuntu0.1-esm1.md) | Dec 2, 2022 |
| Linux | libdcmtk16 Ubuntu 22.04.1 LTS (jammy) | 3.6.6-5ubuntu0.1~esm1 | [libdcmtk16 3.6.6-5ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libdcmtk16-3.6.6-5ubuntu0.1-esm1.md) | Dec 2, 2022 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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