{"cve":"CVE-2021-1403","nvd":{"published":"2021-03-24T20:15:14.320","modified":"2026-06-17T03:31:41.750","status":"Modified","description":"A vulnerability in the web UI feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a cross-site WebSocket hijacking (CSWSH) attack and cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient HTTP protections in the web UI on an affected device. An attacker could exploit this vulnerability by persuading an authenticated user of the web UI to follow a crafted link. A successful exploit could allow the attacker to corrupt memory on the affected device, forcing it to reload and causing a DoS condition.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H","score":7.4},"cwes":["CWE-1021","CWE-345"],"references":["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-cswsh-FKk9AzT5","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-cswsh-FKk9AzT5"],"products":["cisco:ios_xe"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-1403","score":0.00621,"percentile":0.49796,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}