{"id":"CVE-2021-22890","state":"PUBLISHED","title":"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 HTT","description":"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.","publishedAt":"2021-04-01T17:46:17.000Z","updatedAt":"2026-10-14T10:15:43.043Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","source":"CISA-ADP"},"assigner":"hackerone","products":["n/a https://github.com/curl/curl"],"affected":[{"vendor":"n/a","product":"https://github.com/curl/curl","versions":[{"version":"7.63.0 to and including 7.75.0","status":"affected"}]}],"references":["https://hackerone.com/reports/1129529","https://curl.se/docs/CVE-2021-22890.html","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ITVWPVGLFISU5BJC2BXBRYSDXTXE2YGC/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQUIOYX2KUU6FIUZVB5WWZ6JHSSYSQWJ/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ZC5BMIOKLBQJSFCHEDN2G2C2SH274BP/","https://security.gentoo.org/glsa/202105-36","https://www.oracle.com//security-alerts/cpujul2021.html","https://security.netapp.com/advisory/ntap-20210521-0007/","https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf","https://cert-portal.siemens.com/productcert/html/ssa-389290.html","https://cert-portal.siemens.com/productcert/html/ssa-398330.html"],"weaknesses":["CWE-300"],"ingestedAt":"2026-10-29T19:48:02.192Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/22xxx/CVE-2021-22890.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-22890","state":"PUBLISHED","datePublished":"2021-04-01T17:46:17.000Z","dateUpdated":"2026-10-14T10:15:43.043Z","assignerShortName":"hackerone","assignerOrgId":"36234546-b8fa-4601-9d6f-f4e334aa8ea1","dateReserved":"2021-01-06T00:00:00.000Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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. 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