CVE-2021-29504 Improper Certificate Validation in WP-CLI framework
Attackers can bypass TLS certificate validation in WP-CLI to intercept traffic and push malicious updates to WordPress instances or the CLI itself.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-29504?
CVE-2021-29504 is a critical vulnerability in wp-cli, published on 7 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
WP-CLI is the command-line interface for WordPress. An 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. The 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. The 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. https://github.com/wp-cli/wp-cli/pull/5523 has also added an `--insecure` flag to the `cli update` command to counter this breaking change. There is no direct workaround for the default insecure behavior of `wp-cli/wp-cli` versions before 2.5.0. The 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.
Weakness: CWE-295
Which versions are affected by CVE-2021-29504?
3 open source packages ship an affected version, including wp-cli/wp-cli and wp-cli. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
wp-cli/wp-cli Packagist | From 0.12.0 | 2.5.0 |
wp-cli/wp-cli Packagist | From 0.12.0 | 2.5.0 |
wp-cli Bitnami | From 0.12.0 | 2.5.0 |
Linux distribution packages (1)
wp-cli openSUSE:Tumbleweed | All versions | 2.5.0-1.2 |
Products include Wp-Cli Wp-Cli.
How do I fix CVE-2021-29504?
Upgrade wp-cli/wp-cli to 2.5.0 or later.
Is CVE-2021-29504 being exploited?
There is no known exploitation of CVE-2021-29504 in the wild and no public exploit code.
Sources
Also known as BIT-wp-cli-2021-29504, GHSA-rwgm-f83r-v3qj, openSUSE-SU-2024:11514-1.