Low 3.7Published Aug 5, 2021

CVE-2021-22924libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of them matches the setup.Due to errors in the logic, the config matching function did not take…

Updated under an hour ago (Oct 27, 2026, 2:10 PM ET)

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It affects Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP and 35 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP

Exploited in the last 30 days

libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of them matches the setup.Due to errors in the logic, the config matching function did not take 'issuercert' into account and it compared the involved paths *case insensitively*,which could lead to libcurl reusing wrong connections.File paths are, or can be, case sensitive on many systems but not all, and caneven vary depending on used file systems.The comparison also didn't include the 'issuer cert' which a transfer can setto qualify how to verify the server certificate.

CVSS: 3.7 LOW (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness (CWE): CWE-20
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: hackerone
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
haxx libcurl haxx:libcurl	from 7.10.4 before 7.77.0	NVD
fedoraproject fedora fedoraproject:fedora	33	NVD
debian debian_linux debian:debian_linux	9.0; 10.0; 11.0	NVD
netapp cloud_backup netapp:cloud_backup	all versions	NVD
netapp clustered_data_ontap netapp:clustered_data_ontap	all versions	NVD
netapp solidfire_&_hci_management_node netapp:solidfire_&_hci_management_node	all versions	NVD
netapp solidfire_baseboard_management_controller_firmware netapp:solidfire_baseboard_management_controller_firmware	all versions	NVD
1–10 of 36

References

References

https://hackerone.com/reports/1223565	x-refsource-misc, exploit, issue-tracking, patch, third-party-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FRUCW2UVNYUDZF72DQLFQR4PJEC6CF7V/	vendor-advisory, x-refsource-fedora, mailing-list, third-party-advisory
https://lists.debian.org/debian-lts-announce/2021/08/msg00017.html	mailing-list, x-refsource-mlist, third-party-advisory
https://lists.apache.org/thread.html/r61db8e7dcb56dc000a5387a88f7a473bacec5ee01b9ff3f55308aacc%40%3Cdev.kafka.apache.org%3E	mailing-list, x-refsource-mlist, third-party-advisory
https://lists.apache.org/thread.html/r61db8e7dcb56dc000a5387a88f7a473bacec5ee01b9ff3f55308aacc%40%3Cusers.kafka.apache.org%3E	mailing-list, x-refsource-mlist, third-party-advisory
https://lists.apache.org/thread.html/rbf4ce74b0d1fa9810dec50ba3ace0caeea677af7c27a97111c06ccb7%40%3Cusers.kafka.apache.org%3E	mailing-list, x-refsource-mlist, third-party-advisory
https://lists.apache.org/thread.html/rbf4ce74b0d1fa9810dec50ba3ace0caeea677af7c27a97111c06ccb7%40%3Cdev.kafka.apache.org%3E	mailing-list, x-refsource-mlist, third-party-advisory
https://www.oracle.com/security-alerts/cpuoct2021.html	x-refsource-misc, patch, third-party-advisory
https://security.netapp.com/advisory/ntap-20210902-0003/	x-refsource-confirm, third-party-advisory
https://www.oracle.com/security-alerts/cpujan2022.html	x-refsource-misc, patch, third-party-advisory
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.