{"id":"CVE-2020-24356","aliases":["GHSA-hgwp-4vp4-qmm2","GO-2022-0845"],"url":"https://o3.security/vulnerability/CVE-2020-24356","summary":"Local Privilege Escalation in cloudflared","details":"In `cloudflared` versions < 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.","published":"2020-10-02T15:15:12.483Z","modified":"2026-07-09T01:31:01.891843Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/cloudflare/cloudflared","fixedVersion":"0.0.0-20200820025921-9323844ea773"}],"fix":{"url":"https://github.com/cloudflare/cloudflared/commit/9323844ea773b1444460fa09295ab8c01a88d97e","label":"cloudflare/cloudflared@9323844"},"references":[{"type":"ADVISORY","url":"https://github.com/cloudflare/cloudflared/security/advisories/GHSA-hgwp-4vp4-qmm2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-24356"},{"type":"WEB","url":"https://github.com/cloudflare/cloudflared/commit/9323844ea773b1444460fa09295ab8c01a88d97e"},{"type":"PACKAGE","url":"https://github.com/cloudflare/cloudflared"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T01:31:01.891843Z"}}