CVE-2021-26734 - Vulnerability Details - OpenCVE

Description

Zscaler Client Connector Installer on Windows before version 3.4.0.124 improperly handled directory junctions during uninstallation. A local adversary may be able to delete folders in an elevated context.

Published: 2023-10-23

Score: 4.4 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

No analysis available yet.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Zscaler

Client Connector

unaffected

Version	Status	Constraints
`0`	affected	< 3.4.0.124

Configuration 1 [-]

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

No data.

No data available yet.

Remediation

No remediation available yet.

Tracking

Sign in to view the affected projects.

Advisories

Source	ID	Title
EUVD	EUVD-2021-13521	Zscaler Client Connector Installer on Windows before version 3.4.0.124 improperly handled directory junctions during uninstallation. A local adversary may be able to delete folders in an elevated context.

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

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 0.00023.

Exploitation none

Automatable no

Technical Impact partial

References

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

History

Wed, 18 Sep 2024 08:30:00 +0000

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

Subscriptions

Zscaler Client Connector

MITRE

Status: PUBLISHED

Assigner: Zscaler

Published: 2023-10-23T13:18:36.569Z

Updated: 2024-09-17T13:46:22.720Z

Reserved: 2021-02-05T20:34:27.823Z

Link: CVE-2021-26734

Vulnrichment

Updated: 2024-08-03T20:33:40.861Z

NVD

Status : Modified

Published: 2023-10-23T14:15:08.927

Modified: 2024-11-21T05:56:46.477

Link: CVE-2021-26734

Redhat

No data.

OpenCVE Enrichment

No data.

Weaknesses

{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2021-26734", "assignerOrgId": "73c6f63b-efac-410d-a0a9-569700f85a04", "state": "PUBLISHED", "assignerShortName": "Zscaler", "dateReserved": "2021-02-05T20:34:27.823Z", "datePublished": "2023-10-23T13:18:36.569Z", "dateUpdated": "2024-09-17T13:46:22.720Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Client Connector", "vendor": "Zscaler", "versions": [{"lessThan": "3.4.0.124", "status": "affected", "version": "0", "versionType": "custom"}]}], "credits": [{"lang": "en", "type": "finder", "user": "00000000-0000-4000-9000-000000000000", "value": "Benjamin Dubost, LMCO"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Zscaler Client Connector Installer on Windows before version 3.4.0.124 improperly handled directory junctions during uninstallation. A local adversary may be able to delete folders in an elevated context.<br>\n\n<br>\n\n"}], "value": "Zscaler Client Connector Installer on Windows before version 3.4.0.124 improperly handled directory junctions during uninstallation. A local adversary may be able to delete folders in an elevated context.\n\n\n\n\n\n"}], "impacts": [{"capecId": "CAPEC-233", "descriptions": [{"lang": "en", "value": "CAPEC-233 Privilege Escalation"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 4.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H", "version": "3.1"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-269", "description": "CWE-269 Improper Privilege Management", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "73c6f63b-efac-410d-a0a9-569700f85a04", "shortName": "Zscaler", "dateUpdated": "2023-10-23T13:18:36.569Z"}, "references": [{"url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021"}], "source": {"discovery": "UNKNOWN"}, "title": "Junction Delete leading to elevation of privilege", "x_generator": {"engine": "Vulnogram 0.1.0-dev"}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-03T20:33:40.861Z"}, "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": "2024-09-11T20:17:30.565473Z", "id": "CVE-2021-26734", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-17T13:46:22.720Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-03T20:33:40.861Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2021-26734", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-09-11T20:17:30.565473Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-17T13:46:11.512Z"}}], "cna": {"title": "Junction Delete leading to elevation of privilege", "source": {"discovery": "UNKNOWN"}, "credits": [{"lang": "en", "type": "finder", "user": "00000000-0000-4000-9000-000000000000", "value": "Benjamin Dubost, LMCO"}], "impacts": [{"capecId": "CAPEC-233", "descriptions": [{"lang": "en", "value": "CAPEC-233 Privilege Escalation"}]}], "metrics": [{"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.4, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "REQUIRED", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "Zscaler", "product": "Client Connector", "versions": [{"status": "affected", "version": "0", "lessThan": "3.4.0.124", "versionType": "custom"}], "defaultStatus": "unaffected"}], "references": [{"url": "https://help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2021"}], "x_generator": {"engine": "Vulnogram 0.1.0-dev"}, "descriptions": [{"lang": "en", "value": "Zscaler Client Connector Installer on Windows before version 3.4.0.124 improperly handled directory junctions during uninstallation. A local adversary may be able to delete folders in an elevated context.\n\n\n\n\n\n", "supportingMedia": [{"type": "text/html", "value": "Zscaler Client Connector Installer on Windows before version 3.4.0.124 improperly handled directory junctions during uninstallation. A local adversary may be able to delete folders in an elevated context.<br>\n\n<br>\n\n", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-269", "description": "CWE-269 Improper Privilege Management"}]}], "providerMetadata": {"orgId": "73c6f63b-efac-410d-a0a9-569700f85a04", "shortName": "Zscaler", "dateUpdated": "2023-10-23T13:18:36.569Z"}}}, "cveMetadata": {"cveId": "CVE-2021-26734", "state": "PUBLISHED", "dateUpdated": "2024-09-17T13:46:22.720Z", "dateReserved": "2021-02-05T20:34:27.823Z", "assignerOrgId": "73c6f63b-efac-410d-a0a9-569700f85a04", "datePublished": "2023-10-23T13:18:36.569Z", "assignerShortName": "Zscaler"}, "dataVersion": "5.1"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:windows:*:*", "matchCriteriaId": "8318DD99-D4B2-4917-AAB3-56D65DE97B57", "versionEndExcluding": "3.4.0.124", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "descriptions": [{"lang": "en", "value": "Zscaler Client Connector Installer on Windows before version 3.4.0.124 improperly handled directory junctions during uninstallation. A local adversary may be able to delete folders in an elevated context.\n\n\n\n\n\n"}, {"lang": "es", "value": "El instalador de Zscaler Client Connector en Windows anterior a la versi\u00f3n 3.4.0.124 manejaba incorrectamente las uniones de directorios durante la desinstalaci\u00f3n. Un adversario local puede eliminar carpetas en un contexto elevado."}], "id": "CVE-2021-26734", "lastModified": "2024-11-21T05:56:46.477", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 4.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 0.8, "impactScore": 3.6, "source": "cve@zscaler.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2023-10-23T14:15:08.927", "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-269"}], "source": "cve@zscaler.com", "type": "Secondary"}, {"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}