{"cve":"CVE-2021-31520","nvd":{"published":"2021-05-10T11:15:08.003","modified":"2026-06-17T03:51:57.137","status":"Modified","description":"A weak session token authentication bypass vulnerability in Trend Micro IM Security 1.6 and 1.6.5 could allow an remote attacker to guess currently logged-in administrators' session session token in order to gain access to the product's web management interface.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.1},"cwes":["CWE-287"],"references":["https://success.trendmicro.com/solution/000286439","https://www.zerodayinitiative.com/advisories/ZDI-21-525/","https://success.trendmicro.com/solution/000286439","https://www.zerodayinitiative.com/advisories/ZDI-21-525/"],"products":["trendmicro:im_security"],"source":"nvd","synced_at":"2026-10-19T21:18:09.669877188+00:00"},"epss":{"cve":"CVE-2021-31520","score":0.03901,"percentile":0.90267,"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."]}