# CVE-2021-22945: curl: When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a p...

CVE-2021-22945 is fixed in 4 products on 1 platform, first by curl 7.74.0-1.3ubuntu2, released September 14, 2021. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-22945
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0668
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 14, 2021

## Description

When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | curl Ubuntu 22.04.1 LTS (jammy) | 7.74.0-1.3ubuntu2 | [curl 7.74.0-1.3ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-curl-7.74.0-1.3ubuntu2.md) | Sep 14, 2021 |
| Linux | libcurl3-gnutls Ubuntu 22.04.1 LTS (jammy) | 7.74.0-1.3ubuntu2 | [libcurl3-gnutls 7.74.0-1.3ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl3-gnutls-7.74.0-1.3ubuntu2.md) | Sep 14, 2021 |
| Linux | libcurl3-nss Ubuntu 22.04.1 LTS (jammy) | 7.74.0-1.3ubuntu2 | [libcurl3-nss 7.74.0-1.3ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl3-nss-7.74.0-1.3ubuntu2.md) | Sep 14, 2021 |
| Linux | libcurl4 Ubuntu 22.04.1 LTS (jammy) | 7.74.0-1.3ubuntu2 | [libcurl4 7.74.0-1.3ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl4-7.74.0-1.3ubuntu2.md) | Sep 14, 2021 |

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Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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