CVE-2021-26736 - Vulnerability Details - OpenCVE

Multiple vulnerabilities in the Zscaler Client Connector Installer and Uninstaller for Windows prior to 3.6 allowed execution of binaries from a low privileged path. A local adversary may be able to execute code with SYSTEM privileges.

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00033.

Exploitation none

Automatable no

Technical Impact total

Vendors	Products
Zscaler	Client Connector

Configuration 1 [-]

cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:windows:*:*

No data.

No data.

Advisories

Source	ID	Title
EUVD	EUVD-2021-13523	Multiple vulnerabilities in the Zscaler Client Connector Installer and Uninstaller for Windows prior to 3.6 allowed execution of binaries from a low privileged path. A local adversary may be able to execute code with SYSTEM privileges.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References

Link	Providers
https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021

History

Tue, 04 Mar 2025 03:45:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

MITRE

Status: PUBLISHED

Assigner: Zscaler

Published: 2023-10-23T13:21:12.518Z

Updated: 2025-02-27T20:40:09.700Z

Reserved: 2021-02-05T20:34:27.824Z

Link: CVE-2021-26736

Vulnrichment

Updated: 2024-08-03T20:33:40.746Z

NVD

Status : Modified

Published: 2023-10-23T14:15:09.063

Modified: 2024-11-21T05:56:46.730

Link: CVE-2021-26736

Redhat

No data.

OpenCVE Enrichment

No data.

{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2021-26736", "assignerOrgId": "73c6f63b-efac-410d-a0a9-569700f85a04", "state": "PUBLISHED", "assignerShortName": "Zscaler", "dateReserved": "2021-02-05T20:34:27.824Z", "datePublished": "2023-10-23T13:21:12.518Z", "dateUpdated": "2025-02-27T20:40:09.700Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "platforms": ["Windows"], "product": "Client Connector", "vendor": "Zscaler", "versions": [{"lessThan": "3.6", "status": "affected", "version": "0", "versionType": "custom"}]}], "credits": [{"lang": "en", "type": "finder", "user": "00000000-0000-4000-9000-000000000000", "value": "LMCO Red Team"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Multiple vulnerabilities in the Zscaler Client Connector Installer and Uninstaller for Windows prior to 3.6 allowed execution of binaries from a low privileged path. A local adversary may be able to execute code with SYSTEM privileges.\n\n<br>"}], "value": "Multiple vulnerabilities in the Zscaler Client Connector Installer and Uninstaller for Windows prior to 3.6 allowed execution of binaries from a low privileged path. A local adversary may be able to execute code with SYSTEM privileges.\n\n\n"}], "impacts": [{"capecId": "CAPEC-234", "descriptions": [{"lang": "en", "value": "CAPEC-234 Hijacking a privileged process"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 6.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-20", "description": "CWE-20 Improper Input Validation", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "73c6f63b-efac-410d-a0a9-569700f85a04", "shortName": "Zscaler", "dateUpdated": "2023-10-23T13:21:19.182Z"}, "references": [{"url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021"}], "source": {"discovery": "UNKNOWN"}, "title": "ZApp Installer Privilege Escalation Vulnerabilities", "x_generator": {"engine": "Vulnogram 0.1.0-dev"}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-03T20:33:40.746Z"}, "title": "CVE Program Container", "references": [{"url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021", "tags": ["x_transferred"]}]}, {"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2025-02-26T21:49:29.077116Z", "id": "CVE-2021-26736", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-27T20:40:09.700Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2021-26736", "assignerOrgId": "73c6f63b-efac-410d-a0a9-569700f85a04", "state": "PUBLISHED", "assignerShortName": "Zscaler", "dateReserved": "2021-02-05T20:34:27.824Z", "datePublished": "2023-10-23T13:21:12.518Z", "dateUpdated": "2025-02-27T20:40:09.700Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "platforms": ["Windows"], "product": "Client Connector", "vendor": "Zscaler", "versions": [{"lessThan": "3.6", "status": "affected", "version": "0", "versionType": "custom"}]}], "credits": [{"lang": "en", "type": "finder", "user": "00000000-0000-4000-9000-000000000000", "value": "LMCO Red Team"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Multiple vulnerabilities in the Zscaler Client Connector Installer and Uninstaller for Windows prior to 3.6 allowed execution of binaries from a low privileged path. A local adversary may be able to execute code with SYSTEM privileges.\n\n<br>"}], "value": "Multiple vulnerabilities in the Zscaler Client Connector Installer and Uninstaller for Windows prior to 3.6 allowed execution of binaries from a low privileged path. A local adversary may be able to execute code with SYSTEM privileges.\n\n\n"}], "impacts": [{"capecId": "CAPEC-234", "descriptions": [{"lang": "en", "value": "CAPEC-234 Hijacking a privileged process"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 6.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-20", "description": "CWE-20 Improper Input Validation", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "73c6f63b-efac-410d-a0a9-569700f85a04", "shortName": "Zscaler", "dateUpdated": "2023-10-23T13:21:19.182Z"}, "references": [{"url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021"}], "source": {"discovery": "UNKNOWN"}, "title": "ZApp Installer Privilege Escalation Vulnerabilities", "x_generator": {"engine": "Vulnogram 0.1.0-dev"}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-03T20:33:40.746Z"}, "title": "CVE Program Container", "references": [{"url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021", "tags": ["x_transferred"]}]}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-26736", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2025-02-26T21:49:29.077116Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-26T19:57:15.620Z"}}]}}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:windows:*:*", "matchCriteriaId": "B3A7E628-F74C-46BC-A5E5-25402F2B90D8", "versionEndExcluding": "3.6", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "descriptions": [{"lang": "en", "value": "Multiple vulnerabilities in the Zscaler Client Connector Installer and Uninstaller for Windows prior to 3.6 allowed execution of binaries from a low privileged path. A local adversary may be able to execute code with SYSTEM privileges.\n\n\n"}, {"lang": "es", "value": "M\u00faltiples vulnerabilidades en Zscaler Client Connector Installer and Uninstaller para Windows anteriores a 3.6 permit\u00edan la ejecuci\u00f3n de archivos binarios desde una ruta con pocos privilegios. Un adversario local puede ejecutar c\u00f3digo con privilegios de SYSTEM."}], "id": "CVE-2021-26736", "lastModified": "2024-11-21T05:56:46.730", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 6.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 0.8, "impactScore": 5.9, "source": "cve@zscaler.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2023-10-23T14:15:09.063", "references": [{"source": "cve@zscaler.com", "tags": ["Release Notes"], "url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Release Notes"], "url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021"}], "sourceIdentifier": "cve@zscaler.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}], "source": "cve@zscaler.com", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-22"}], "source": "nvd@nist.gov", "type": "Primary"}]}