{"id":"CVE-2021-22901","revision":"de2bf00dee144b1e95c21c23ec314dcc","records":[{"revision":"de2bf00dee144b1e95c21c23ec314dcc","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2021-22901","aliases":[],"title":"curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session ticket arrives over a connection. A malicious server can use this in rare unfortunate circumstances t…","description":"curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session ticket arrives over a connection. A malicious server can use this in rare unfortunate circumstances to potentially reach remote code execution in the client. When libcurl at run-time sets up support for TLS 1.3 session tickets on a connection using OpenSSL, it stores pointers to the transfer in-memory object for later retrieval when a session ticket arrives. If the connection is used by multiple transfers (like with a reused HTTP/1.1 connection or multiplexed HTTP/2 connection) that first transfer object might be freed before the new session is established on that connection and then the function will access a memory buffer that might be freed. When using that memory, libcurl might even call a function pointer in the object, making it possible for a remote code execution if the server could somehow manage to get crafted memory content into the correct place in memory.","state":0,"publishedAt":"2021-06-11T15:49:38+00:00","modifiedAt":"2026-10-14T10:31:25.845+00:00","affected":[{"ecosystem":"Vendor product","name":"https://github.com/curl/curl","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"https://github.com/curl/curl\",\n                    \"vendor\": \"n/a\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"7.75.0 through 7.76.1\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://hackerone.com/reports/1180380","https://curl.se/docs/CVE-2021-22901.html","https://github.com/curl/curl/commit/7f4a9a9b2a49547eae24d2e19bc5c346e9026479","https://www.oracle.com//security-alerts/cpujul2021.html","https://security.netapp.com/advisory/ntap-20210723-0001/","https://www.oracle.com/security-alerts/cpujan2022.html","https://security.netapp.com/advisory/ntap-20210727-0007/","https://www.oracle.com/security-alerts/cpuapr2022.html","https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf","https://cert-portal.siemens.com/productcert/pdf/ssa-732250.pdf"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2021-22901","license":"CVE Program Terms of Use","key":"cve-program:CVE-2021-22901","identifiers":["CVE-2021-22901"]},"retained":false,"historicalAffected":[]}],"coverage":[]}