CVE-2021-4461CWE-306

Seeyon Zhiyuan OA Web Application System < 7.0 SP1 Authentication Bypass

Critical · published October 30, 2025

CVSS v4.0
9.3
EPSS
0%
Percentile
41.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
9.3 · CRITICAL
Vector
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
EPSS
0.00490 · 41.2th percentile
Weakness
CWE-306 · Missing Authentication for Critical Function
Published
2025-10-30T21:16Z
EPSS history
Timeline
  • 30 OCT 21:16Z
    Seeyon Zhiyuan OA Web Application System < 7.0 SP1 Authentication Bypass
    cvelistv5