{"cve":"CVE-2021-27771","nvd":{"published":"2022-05-12T22:15:11.880","modified":"2026-06-17T03:45:25.793","status":"Modified","description":"User SID can be modified resulting in an Arbitrary File Upload or deletion of directories causing a Denial of Service. When interacting in a normal matter with the Sametime chat application, users hold a cookie containing their session ID (SID). This value is also used when sending chat messages, receiving notifications and/or transferring files.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H","score":7.6},"cwes":["CWE-434","CWE-22"],"references":["https://support.hcltechsw.com/csm?id=kb_article&sysparm_article=KB0097430","https://support.hcltechsw.com/csm?id=kb_article&sysparm_article=KB0097430"],"products":["hcltech:sametime"],"source":"nvd","synced_at":"2026-10-19T21:31:59.322382750+00:00"},"epss":{"cve":"CVE-2021-27771","score":0.00732,"percentile":0.54348,"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."]}