Medium 4.3Published Apr 1, 2021

CVE-2021-22890curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets.

Updated under an hour ago (Oct 28, 2026, 11:20 PM ET)

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It affects Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP and 13 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

curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly "short-cut" the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.

CVSS: 4.3 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-300
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 7.63.0 through 7.75.0	NVD
fedoraproject fedora fedoraproject:fedora	32; 33; 34	NVD
netapp hci_management_node netapp:hci_management_node	all versions	NVD
netapp solidfire netapp:solidfire	all versions	NVD
netapp hci_storage_node netapp:hci_storage_node	all versions	NVD
broadcom fabric_operating_system broadcom:fabric_operating_system	all versions	NVD
debian debian_linux debian:debian_linux	9.0	NVD
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References

References

https://hackerone.com/reports/1129529	x-refsource-misc, exploit, issue-tracking, patch, third-party-advisory
https://curl.se/docs/CVE-2021-22890.html	x-refsource-misc, patch, vendor-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVWPVGLFISU5BJC2BXBRYSDXTXE2YGC/	vendor-advisory, x-refsource-fedora, mailing-list, third-party-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQUIOYX2KUU6FIUZVB5WWZ6JHSSYSQWJ/	vendor-advisory, x-refsource-fedora, mailing-list, third-party-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/	vendor-advisory, x-refsource-fedora, mailing-list, third-party-advisory
https://security.gentoo.org/glsa/202105-36	vendor-advisory, x-refsource-gentoo, third-party-advisory
https://www.oracle.com//security-alerts/cpujul2021.html	x-refsource-misc, third-party-advisory
https://security.netapp.com/advisory/ntap-20210521-0007/	x-refsource-confirm, third-party-advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf	x-refsource-confirm, patch, third-party-advisory
https://cert-portal.siemens.com/productcert/html/ssa-389290.html
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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.