CVE-2021-4461 (GCVE-0-2021-4461)
Vulnerability from cvelistv5 – Published: 2025-10-30 21:16 – Updated: 2025-11-28 19:17 X_Known Exploited VulnerabilityTitle
Seeyon Zhiyuan OA Web Application System < 7.0 SP1 Authentication Bypass
Summary
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.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-11-28 19:16 UTC
CWE
- CWE-306 - Missing Authentication for Critical Function
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://mp.weixin.qq.com/s/0AqdfTrZUVrwTMbKEKresg | exploit |
| https://github.com/chaitin/xray/blob/f90cf321bc4d… | exploit |
| https://github.com/projectdiscovery/nuclei-templa… | exploit |
| https://www.vulncheck.com/advisories/seeyon-zhiyu… | third-party-advisory |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Seeyon | Zhiyuan OA Web Application System |
Affected:
0 , ≤ 7.0 SP1
(custom)
cpe:2.3:a:seeyon:zhiyuan_oa_web_application_system:*:*:*:*:*:*:*:* |
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 06d57e76-aa95-42f0-9fb1-3d0572311812
Exploited: Yes
Timestamps
First Seen: 2026-06-01
Asserted: 2026-06-01
Scope
Notes: KEVIntel entry: Seeyon Zhiyuan OA Web Application System < 7.0 SP1 Authentication Bypass | Affected: Seeyon / Zhiyuan OA Web Application System | CVSS: 9.3 (CRITICAL) | EPSS: 0.00551 | Used in malware: unknown | Not yet in CISA KEV: True
Evidence
Type: Public Report
Signal: Successful Exploitation
Confidence: 70%
Source: kevintel
Details
| Feed | KEVIntel (kevintel.com) |
|---|---|
| Title | Seeyon Zhiyuan OA Web Application System < 7.0 SP1 Authentication Bypass |
| Vendor | Seeyon |
| Product | Zhiyuan OA Web Application System |
| Added Date | 2026-06-01T10:43:10.427Z |
| Cvss Score | 9.3 |
| Epss Score | 0.00551 |
| Cvss Severity | CRITICAL |
| Epss Percentile | 0.41663 |
| Used In Malware | unknown |
| Ahead Of Cisa Kev | None |
| Not Yet In Cisa Kev | True |
References
Created: 2026-06-19 12:42 UTC
| Updated: 2026-06-19 12:42 UTC
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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