{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-4461","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2025-10-30T20:08:37.632Z","datePublished":"2025-10-30T21:16:23.161Z","dateUpdated":"2025-11-28T19:17:19.543Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unknown","modules":["thirdpartyController.do – `enc` parameter decoding (LightWeightEncoder) and parsing"],"product":"Zhiyuan OA Web Application System","vendor":"Seeyon","versions":[{"lessThanOrEqual":"7.0 SP1","status":"affected","version":"0","versionType":"custom"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:seeyon:zhiyuan_oa_web_application_system:*:*:*:*:*:*:*:*","versionEndIncluding":"7.0_sp1","versionStartIncluding":"0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"OR"}],"credits":[{"lang":"en","type":"finder","value":"Anonymous User via WeChat"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Seeyon Zhiyuan OA Web Application System versions up to and including 7.0 SP1&nbsp;improperly decode and parse the `enc` parameter in thirdpartyController.do. The decoded map values can influence session attributes without sufficient authentication/authorization checks, enabling attackers to assign a session to arbitrary user IDs. VulnCheck has observed this vulnerability being exploited in the wild as of 2025-10-30 at 00:30:40.855917 UTC."}],"value":"Seeyon Zhiyuan OA Web Application System versions up to and including 7.0 SP1 improperly decode and parse the `enc` parameter in thirdpartyController.do. The decoded map values can influence session attributes without sufficient authentication/authorization checks, enabling attackers to assign a session to arbitrary user IDs. VulnCheck has observed this vulnerability being exploited in the wild as of 2025-10-30 at 00:30:40.855917 UTC."}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":9.3,"baseSeverity":"CRITICAL","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-306","description":"CWE-306 Missing Authentication for Critical Function","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2025-10-30T21:18:19.787Z"},"references":[{"tags":["exploit"],"url":"https://mp.weixin.qq.com/s/0AqdfTrZUVrwTMbKEKresg"},{"tags":["exploit"],"url":"https://github.com/chaitin/xray/blob/f90cf321bc4d294bbf6625a9c4853f3bfdf0a384/pocs/seeyon-oa-cookie-leak.yml"},{"tags":["exploit"],"url":"https://github.com/projectdiscovery/nuclei-templates/blob/1ca6b8e6fe225cbd46dcb893dcaee01447afa8c0/http/misconfiguration/seeyon-unauth.yaml#L20"},{"tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/seeyon-zhiyuan-oa-web-application-system-authentication-bypass"}],"source":{"discovery":"UNKNOWN"},"tags":["x_known-exploited-vulnerability"],"title":"Seeyon Zhiyuan OA Web Application System < 7.0 SP1 Authentication Bypass","x_generator":{"engine":"Vulnogram 0.4.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2025-11-28T19:16:58.418427Z","id":"CVE-2021-4461","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2025-11-28T19:17:19.543Z"}}]}}