{"id":"CVE-2020-24356","aliases":["EUVD-2021-1103","GHSA-hgwp-4vp4-qmm2","GO-2022-0845"],"status":"published","title":"Local Privilege Escalation in cloudflared","description":"`cloudflared` versions prior to 2020.8.1 contain a local privilege escalation vulnerability on Windows systems. When run on a Windows system, `cloudflared` searches for configuration files which could be abused by a malicious entity to execute commands as a privileged user. Version 2020.8.1 fixes this issue.","severity":{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00348,"percentile":0.2877,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-427"],"published":"2020-10-02T14:16:23Z","modified":"2026-10-20T10:52:51Z","fixes":[{"ecosystem":"Go","package":"github.com/cloudflare/cloudflared","fixed_in":["0.0.0-20200820025921-9323844ea773"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/cloudflare/cloudflared","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.0.0-20200820025921-9323844ea773"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/cloudflare/cloudflared","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.0-20200820025921-9323844ea773"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/cloudflare/cloudflared","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.0-20200820025921-9323844ea773"}]}]}],"products":[{"vendor":"cloudflare","product":"cloudflared"}],"references":[{"url":"https://github.com/cloudflare/cloudflared/security/advisories/GHSA-hgwp-4vp4-qmm2","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-24356","tags":["advisory"]},{"url":"https://github.com/cloudflare/cloudflared/commit/9323844ea773b1444460fa09295ab8c01a88d97e","tags":["web","fix"]},{"url":"https://github.com/advisories/GHSA-hgwp-4vp4-qmm2"},{"url":"https://github.com/cloudflare/cloudflared","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2020-24356","title":"Local Privilege Escalation in cloudflared","description":"`cloudflared` versions prior to 2020.8.1 contain a local privilege escalation vulnerability on Windows systems. When run on a Windows system, `cloudflared` searches for configuration files which could be abused by a malicious entity to execute commands as a privileged user. Version 2020.8.1 fixes this issue.","status":"published","published":"2020-10-02T14:16:23.809Z","modified":"2024-09-17T01:46:28.741Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N","level":"medium","assessor":"cna"}],"updated_at":"2026-11-02T14:35:54.468882Z"}],"euvd":[{"id":"EUVD-2021-1103","description":"`cloudflared` versions prior to 2020.8.1 contain a local privilege escalation vulnerability on Windows systems. When run on a Windows system, `cloudflared` searches for configuration files which could be abused by a malicious entity to execute commands as a privileged user. Version 2020.8.1 fixes this issue.","status":"published","published":"2020-10-02T14:16:23Z","modified":"2024-09-17T01:46:28Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N","level":"medium"}],"updated_at":"2026-11-03T00:28:46.561775Z"}],"ghsa":[{"id":"GHSA-hgwp-4vp4-qmm2","title":"Local Privilege Escalation in cloudflared","description":"In `cloudflared` versions \u003c 2020.8.1 (corresponding to 0.0.0-20200820025921-9323844ea773 on pkg.go.dev) on Windows, if an administrator has started `cloudflared` and set it to read configuration files from a certain directory, an unprivileged user can exploit a misconfiguration in order to escalate privileges and execute system-level commands. The misconfiguration was due to the way that `cloudflared` reads its configuration file. One of the locations that `cloudflared` reads from (C:\\etc\\) is not a secure by default directory due to the fact that Windows does not enforce access controls on this directory without further controls applied. A malformed config.yaml file can be written by any user. Upon reading this config, `cloudflared` would output an error message to a log file defined in the malformed config. The user-controlled log file location could be set to a specific location that Windows will execute when any user logs in.","status":"published","published":"2021-05-24T16:56:35Z","modified":"2023-03-02T21:10:46Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-427"],"updated_at":"2026-11-02T14:36:46.526285Z"}],"nvd":[{"id":"CVE-2020-24356","description":"`cloudflared` versions prior to 2020.8.1 contain a local privilege escalation vulnerability on Windows systems. When run on a Windows system, `cloudflared` searches for configuration files which could be abused by a malicious entity to execute commands as a privileged user. Version 2020.8.1 fixes this issue.","status":"published","published":"2020-10-02T15:15:12.483Z","modified":"2026-06-17T03:05:25.517Z","cvss":[{"version":"3.1","score":6.4,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":4.6,"vector":"AV:L/AC:L/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-427"],"updated_at":"2026-11-02T14:06:17.70091Z"}],"osv":[{"id":"CVE-2020-24356","description":"`cloudflared` versions prior to 2020.8.1 contain a local privilege escalation vulnerability on Windows systems. When run on a Windows system, `cloudflared` searches for configuration files which could be abused by a malicious entity to execute commands as a privileged user. Version 2020.8.1 fixes this issue.","status":"published","published":"2020-10-02T15:15:12.483Z","modified":"2026-10-20T10:52:51.840899252Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:15.879068Z"},{"id":"GHSA-hgwp-4vp4-qmm2","title":"Local Privilege Escalation in cloudflared","description":"In `cloudflared` versions \u003c 2020.8.1 (corresponding to 0.0.0-20200820025921-9323844ea773 on pkg.go.dev) on Windows, if an administrator has started `cloudflared` and set it to read configuration files from a certain directory, an unprivileged user can exploit a misconfiguration in order to escalate privileges and execute system-level commands. The misconfiguration was due to the way that `cloudflared` reads its configuration file. One of the locations that `cloudflared` reads from (C:\\etc\\) is not a secure by default directory due to the fact that Windows does not enforce access controls on this directory without further controls applied. A malformed config.yaml file can be written by any user. Upon reading this config, `cloudflared` would output an error message to a log file defined in the malformed config. The user-controlled log file location could be set to a specific location that Windows will execute when any user logs in.","status":"published","published":"2021-05-24T16:56:35Z","modified":"2026-09-10T03:49:14.744293855Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-427"],"updated_at":"2026-11-02T15:46:49.28217Z"},{"id":"GO-2022-0845","title":"Local Privilege Escalation in cloudflared in github.com/cloudflare/cloudflared","description":"Local Privilege Escalation in cloudflared in github.com/cloudflare/cloudflared","status":"published","published":"2024-08-21T15:29:04Z","modified":"2026-03-03T04:52:19.601593Z","updated_at":"2026-11-02T15:47:00.918515Z"}]}}