{"cve":"CVE-2021-3449","nvd":{"published":"2021-03-25T15:15:13.450","modified":"2026-10-08T22:17:11.243","status":"Modified","description":"An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","score":5.9},"cwes":["CWE-476"],"references":["http://www.openwall.com/lists/oss-security/2021/03/27/1","http://www.openwall.com/lists/oss-security/2021/03/27/2","http://www.openwall.com/lists/oss-security/2021/03/28/3","http://www.openwall.com/lists/oss-security/2021/03/28/4","https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf"],"products":["checkpoint:multi-domain_management_firmware","checkpoint:quantum_security_gateway_firmware","checkpoint:quantum_security_management_firmware","debian:debian_linux","fedoraproject:fedora","freebsd:freebsd","mcafee:web_gateway","mcafee:web_gateway_cloud_service","netapp:active_iq_unified_manager","netapp:cloud_volumes_ontap_mediator","netapp:e-series_performance_analyzer","netapp:oncommand_insight","netapp:oncommand_workflow_automation","netapp:ontap_select_deploy_administration_utility","netapp:santricity_smi-s_provider","netapp:snapcenter","netapp:storagegrid","nodejs:node.js","openssl:openssl","oracle:communications_communications_policy_management","oracle:enterprise_manager_for_storage_management","oracle:essbase","oracle:graalvm","oracle:jd_edwards_enterpriseone_tools","oracle:jd_edwards_world_security","oracle:mysql_connectors","oracle:mysql_server","oracle:mysql_workbench","oracle:peoplesoft_enterprise_peopletools","oracle:primavera_unifier","oracle:secure_backup","oracle:secure_global_desktop","oracle:zfs_storage_appliance_kit","siemens:ruggedcom_rcm1224_firmware","siemens:scalance_lpe9403_firmware","siemens:scalance_m-800_firmware","siemens:scalance_s602_firmware","siemens:scalance_s612_firmware","siemens:scalance_s615_firmware","siemens:scalance_s623_firmware","siemens:scalance_s627-2m_firmware","siemens:scalance_sc-600_firmware","siemens:scalance_w1700_firmware","siemens:scalance_w700_firmware","siemens:scalance_xb-200_firmware","siemens:scalance_xc-200_firmware","siemens:scalance_xf-200ba_firmware","siemens:scalance_xm-400_firmware","siemens:scalance_xp-200_firmware","siemens:scalance_xr-300wg_firmware"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-3449","score":0.63542,"percentile":0.99206,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-83mx-573x-5rw9","url":"https://osv.dev/vulnerability/GHSA-83mx-573x-5rw9","summary":"openssl-src NULL pointer Dereference in signature_algorithms processing","modified":"2024-12-16T15:27:00.557120Z","packages":[{"ecosystem":"crates.io","name":"openssl-src","purl":"pkg:cargo/openssl-src","ranges":["<111.15.0"],"fixed":["111.15.0"]}]},{"id":"RUSTSEC-2021-0055","url":"https://osv.dev/vulnerability/RUSTSEC-2021-0055","summary":"NULL pointer deref in signature_algorithms processing","modified":"2024-12-16T15:27:00.557120Z","packages":[{"ecosystem":"crates.io","name":"openssl-src","purl":"pkg:cargo/openssl-src","ranges":[">=0.0.0-0 <111.15.0"],"fixed":["111.15.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}