{"id":"CVE-2021-26737","aliases":["EUVD-2021-13524","GHSA-7x29-jh5v-6wwf"],"status":"published","title":"Privilege Escalation Using PID Reuse in ZCC macOS","description":"The Zscaler Client Connector for macOS prior to 3.6 did not sufficiently validate RPC clients. A local adversary without sufficient privileges may be able to shutdown the Zscaler tunnel by exploiting a race condition.","severity":{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00112,"percentile":0.01403,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-346"],"published":"2023-10-23T13:22:51Z","modified":"2026-06-17T03:43:45Z","products":[{"vendor":"zscaler","product":"client connector"},{"vendor":"zscaler","product":"client_connector"}],"references":[{"url":"https://help.zscaler.com/client-connector/client-connector-app-release-summary-2022?applicable_category=macOS\u0026applicable_version=3.6\u0026deployment_date=2022-01-07\u0026id=1388686","tags":["x_transferred","Release Notes"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26737"},{"url":"https://github.com/advisories/GHSA-7x29-jh5v-6wwf"}],"sources":{"cve":[{"id":"CVE-2021-26737","title":"Privilege Escalation Using PID Reuse in ZCC macOS","description":"The Zscaler Client Connector for macOS prior to 3.6 did not sufficiently validate RPC clients. A local adversary without sufficient privileges may be able to shutdown the Zscaler tunnel by exploiting a race condition.\n\n\n","status":"published","published":"2023-10-23T13:22:51.537Z","modified":"2024-09-11T14:32:14.147Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:32:57.368269Z"}],"euvd":[{"id":"EUVD-2021-13524","description":"The Zscaler Client Connector for macOS prior to 3.6 did not sufficiently validate RPC clients. A local adversary without sufficient privileges may be able to shutdown the Zscaler tunnel by exploiting a race condition.\n\n\n","status":"published","published":"2023-10-23T13:22:51Z","modified":"2024-09-11T14:32:14Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-03T00:55:58.744683Z"}],"ghsa":[{"id":"GHSA-7x29-jh5v-6wwf","title":"The Zscaler Client Connector for macOS prior to 3.6 did not sufficiently validate RPC clients. A...","description":"The Zscaler Client Connector for macOS prior to 3.6 did not sufficiently validate RPC clients. A local adversary without sufficient privileges may be able to shutdown the Zscaler tunnel by exploiting a race condition.\n\n\n","status":"published","published":"2023-10-23T15:30:24Z","modified":"2024-04-04T08:53:02Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:57:02.541362Z"}],"nvd":[{"id":"CVE-2021-26737","description":"The Zscaler Client Connector for macOS prior to 3.6 did not sufficiently validate RPC clients. A local adversary without sufficient privileges may be able to shutdown the Zscaler tunnel by exploiting a race condition.\n\n\n","status":"published","published":"2023-10-23T14:15:09.127Z","modified":"2026-06-17T03:43:45.32Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:07:07.764332Z"}]}}