Description
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
CVSS 4.0 9.3/10
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Seeyon | Zhiyuan OA Web Application System | <= 7.0 SP1 |
References
- https://github.com/chaitin/xray/blob/f90cf321bc4d294bbf6625a9c4853f3bfdf0a384/pocs/seeyon-oa-cookie-leak.yml
- https://github.com/projectdiscovery/nuclei-templates/blob/1ca6b8e6fe225cbd46dcb893dcaee01447afa8c0/http/misconfiguration/seeyon-unauth.yaml#L20
- https://mp.weixin.qq.com/s/0AqdfTrZUVrwTMbKEKresg
- https://www.vulncheck.com/advisories/seeyon-zhiyuan-oa-web-application-system-authentication-bypass
Timeline
- Published
- Oct 30, 2025
- Last modified
- Jun 17, 2026
- NVD status
- Deferred