{"id":"ALPINE-CVE-2021-22901","details":"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.","modified":"2026-09-15T08:17:46.617561043Z","published":"2021-06-11T16:15:11.120Z","upstream":["CVE-2021-22901"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2021-22901"}],"affected":[{"package":{"name":"curl","ecosystem":"Alpine:v3.12","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.13","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.14","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.15","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.16","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.17","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.18","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.19","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.20","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.21","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.22","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}},{"package":{"name":"curl","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/curl?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.75.0"},{"fixed":"7.77.0-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2021-22901.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}