CVE-2021-22945

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*.

CVSS 3.1

9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS

6.7% chance of exploitation in the next 30 days; higher than 93% of CVEs (scores of 2026-10-25)

CWE

CWE-415

Published

2021-09-23

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• apple:macos
• debian:debian_linux
• fedoraproject:fedora
• haxx:libcurl
• netapp:cloud_backup
• netapp:clustered_data_ontap
• netapp:h300e_firmware
• netapp:h300s_firmware
• netapp:h410s_firmware
• netapp:h500e_firmware
• netapp:h500s_firmware
• netapp:h700e_firmware
• netapp:h700s_firmware
• netapp:solidfire_baseboard_management_controller_firmware
• oracle:mysql_server
• siemens:sinec_ins
• splunk:universal_forwarder

References

• http://seclists.org/fulldisclosure/2022/Mar/29
• https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
• https://hackerone.com/reports/1269242
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APOAK4X73EJTAPTSVT7IRVDMUWVXNWGD/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RWLEC6YVEM2HWUBX67SDGPSY4CQB72OE/

Check your stackJSON