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 Vulnerability
VLAI
EPSS
VEX
Title
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:*:*:*:*:*:*:*:* |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2021-4461",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-11-28T19:16:58.418427Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2025-11-28T19:17:19.543Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unknown",
"modules": [
"thirdpartyController.do \u2013 `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\u0026nbsp;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\u00a0improperly 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": {
"dateUpdated": "2025-10-30T21:18:19.787Z",
"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
"shortName": "VulnCheck"
},
"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 \u003c 7.0 SP1 Authentication Bypass",
"x_generator": {
"engine": "Vulnogram 0.4.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
"assignerShortName": "VulnCheck",
"cveId": "CVE-2021-4461",
"datePublished": "2025-10-30T21:16:23.161Z",
"dateReserved": "2025-10-30T20:08:37.632Z",
"dateUpdated": "2025-11-28T19:17:19.543Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2021-4461",
"date": "2026-09-25",
"epss": "0.00595",
"percentile": "0.46155"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unknown",
"modules": [
"thirdpartyController.do \u2013 `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"
}
]
}
],
"source": "disclosure@vulncheck.com"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Seeyon Zhiyuan OA Web Application System versions up to and including 7.0 SP1\u00a0improperly 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."
}
],
"id": "CVE-2021-4461",
"lastModified": "2026-06-17T04:19:48.450",
"metrics": {
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 9.3,
"baseSeverity": "CRITICAL",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"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/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:X",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "disclosure@vulncheck.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-4461",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-11-28T19:16:58.418427Z",
"version": "2.0.3"
}
}
]
},
"published": "2025-10-30T22:15:41.633",
"references": [
{
"source": "disclosure@vulncheck.com",
"url": "https://github.com/chaitin/xray/blob/f90cf321bc4d294bbf6625a9c4853f3bfdf0a384/pocs/seeyon-oa-cookie-leak.yml"
},
{
"source": "disclosure@vulncheck.com",
"url": "https://github.com/projectdiscovery/nuclei-templates/blob/1ca6b8e6fe225cbd46dcb893dcaee01447afa8c0/http/misconfiguration/seeyon-unauth.yaml#L20"
},
{
"source": "disclosure@vulncheck.com",
"url": "https://mp.weixin.qq.com/s/0AqdfTrZUVrwTMbKEKresg"
},
{
"source": "disclosure@vulncheck.com",
"url": "https://www.vulncheck.com/advisories/seeyon-zhiyuan-oa-web-application-system-authentication-bypass"
}
],
"sourceIdentifier": "disclosure@vulncheck.com",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-306"
}
],
"source": "disclosure@vulncheck.com",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"current_release_date": "2025-10-31T22:07:28+00:00",
"cve": "CVE-2021-4461",
"id": "CVE-2021-4461",
"initial_release_date": "2021-01-01T00:00:00+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "Seeyon Zhiyuan OA Web Application System \u003c 7.0 SP1 Authentication Bypass",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-4461.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2021-4461",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-11-28T19:16:58.418427Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2025-10-31T18:34:30.657Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unknown",
"modules": [
"thirdpartyController.do \u2013 `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\u0026nbsp;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\u00a0improperly 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": {
"dateUpdated": "2025-10-30T21:18:19.787Z",
"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
"shortName": "VulnCheck"
},
"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 \u003c 7.0 SP1 Authentication Bypass",
"x_generator": {
"engine": "Vulnogram 0.4.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
"assignerShortName": "VulnCheck",
"cveId": "CVE-2021-4461",
"datePublished": "2025-10-30T21:16:23.161Z",
"dateReserved": "2025-10-30T20:08:37.632Z",
"dateUpdated": "2025-11-28T19:17:19.543Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
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.
Loading…
Loading…
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.
Loading…
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.
Loading…