{"id":"CVE-2021-29504","aliases":["BIT-wp-cli-2021-29504","GHSA-rwgm-f83r-v3qj"],"url":"https://o3.security/vulnerability/CVE-2021-29504","summary":"Improper Certificate Validation in WP-CLI framework","details":"### Impact\nAn improper error handling in HTTPS requests management in WP-CLI version 0.12.0 and later allows remote attackers able to intercept the communication to remotely disable the certificate verification on WP-CLI side, gaining full control over the communication content, including the ability to impersonate update servers and push malicious updates towards WordPress instances controlled by the vulnerable WP-CLI agent, or push malicious updates toward WP-CLI itself.\n\n### Patches\nThe vulnerability stems from the fact that the default behavior of `WP_CLI\\Utils\\http_request()` when encountering a TLS handshake error is to disable certificate validation and retry the same request.\n\nThe default behavior has been changed with version 2.5.0 of WP-CLI and the `wp-cli/wp-cli` framework (via https://github.com/wp-cli/wp-cli/pull/5523) so that the `WP_CLI\\Utils\\http_request()` method accepts an `$insecure` option that is `false` by default and consequently that a TLS handshake failure is a hard error by default. This new default is a breaking change and ripples through to all consumers of `WP_CLI\\Utils\\http_request()`, including those in separate WP-CLI bundled or third-party packages.\n\nhttps://github.com/wp-cli/wp-cli/pull/5523 has also added an `--insecure` flag to the `cli update` command to counter this breaking change.\n\nSubsequent PRs on the command repositories have added an `--insecure` flag to the appropriate commands on the following repositories to counter the breaking change:\n\n* https://github.com/wp-cli/config-command/pull/128\n* https://github.com/wp-cli/core-command/pull/186\n* https://github.com/wp-cli/extension-command/pull/287\n* https://github.com/wp-cli/checksum-command/pull/86\n* https://github.com/wp-cli/package-command/pull/138\n\n### Workarounds\nThere is no direct workaround for the default insecure behavior of `wp-cli/wp-cli` versions before 2.5.0.\n\nThe workaround for dealing with the breaking change in the commands directly affected by the new secure default behavior is to add the `--insecure` flag to manually opt-in to the previous insecure behavior.\n\n### References\n* [CWE: Improper Certificate Validation](https://cwe.mitre.org/data/definitions/295.html)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Join the `#cli` channel in the [WordPress.org Slack](https://make.wordpress.org/chat/) to ask questions or provide feedback.\n","published":"2021-06-07T21:15:08.387Z","modified":"2026-07-09T11:34:54.670474Z","cvss":{"score":7.4,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Packagist","name":"wp-cli/wp-cli","fixedVersion":"2.5.0"}],"fix":{"url":"https://github.com/wp-cli/checksum-command/pull/86","label":"wp-cli/checksum-command#86"},"references":[{"type":"ADVISORY","url":"https://github.com/wp-cli/package-command/pull/138"},{"type":"ADVISORY","url":"https://github.com/wp-cli/wp-cli/security/advisories/GHSA-rwgm-f83r-v3qj"},{"type":"FIX","url":"https://github.com/wp-cli/checksum-command/pull/86"},{"type":"FIX","url":"https://github.com/wp-cli/config-command/pull/128"},{"type":"FIX","url":"https://github.com/wp-cli/core-command/pull/186"},{"type":"FIX","url":"https://github.com/wp-cli/extension-command/pull/287"},{"type":"FIX","url":"https://github.com/wp-cli/wp-cli/pull/5523"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-29504"},{"type":"WEB","url":"https://github.com/FriendsOfPHP/security-advisories/blob/master/wp-cli/wp-cli/CVE-2021-29504.yaml"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T11:34:54.670474Z"}}