CVE-2021-4461
Seeyon Zhiyuan OA Web Application System < 7.0 SP1 Authentication Bypass
Vexday Risk Score
28Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 9.3EPSS 0.6%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
30 Oct 2025Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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.
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
Affected products
Seeyon · Zhiyuan OA Web Application SystemWant to know if your infrastructure is exposed to this?
Talk to TrueHacking →References
https://github.com/chaitin/xray/blob/f90cf321bc4d294bbf6625a9c4853f3bfdf0a384/pocs/seeyon-oa-cookie-leak.ymlhttps://github.com/projectdiscovery/nuclei-templates/blob/1ca6b8e6fe225cbd46dcb893dcaee01447afa8c0/http/misconfiguration/seeyon-unauth.yaml#L20https://mp.weixin.qq.com/s/0AqdfTrZUVrwTMbKEKresghttps://www.vulncheck.com/advisories/seeyon-zhiyuan-oa-web-application-system-authentication-bypass