CVE-2021-22890
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 3.1
- 3.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N - EPSS
- 3.1% chance of exploitation in the next 30 days; higher than 87% of CVEs (scores of 2026-10-25)
- CWEs
- CWE-290, CWE-300
- Published
- Modified
- Record from
- the NVD, synced
Affected
- broadcom:fabric_operating_system
- debian:debian_linux
- fedoraproject:fedora
- haxx:libcurl
- netapp:hci_management_node
- netapp:hci_storage_node
- netapp:solidfire
- oracle:communications_billing_and_revenue_management
- oracle:essbase
- siemens:sinec_infrastructure_network_services
- splunk:universal_forwarder
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
- https://curl.se/docs/CVE-2021-22890.html
- https://hackerone.com/reports/1129529
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVWPVGLFISU5BJC2BXBRYSDXTXE2YGC/