Captchinoo Captcha <= 2.3 - Missing Authorization to Arbitrary Plugin Installation/Activation
Strategic Overview
- Status
- Patched in 2.4
- Affected Version
<= 2.3- CVSS
- 8.8High
- Weakness type
- CWE-285 · Improper Authorization
- CVE
CVE-2021-24189
At a glance
CVE-2021-24189 is a high-severity Improper Authorization vulnerability in the Captchinoo, admin login page protection with Google recaptcha WordPress plugin, affecting versions <= 2.3. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). The root cause is a missing authorization check on a reachable function. The issue is fixed in version 2.4; sites on affected versions should update now. Disclosed April 2021, reported by Bugbang.
Vulnerability Overview
Low privileged users can use the AJAX action 'cp_plugins_do_button_job_later_callback' in the Captchinoo, Google recaptcha for admin login page WordPress plugin before 2.4, to install any plugin (including a specific version) from the WordPress repository, as well as activate arbitrary plugins from the blog, which helps attackers install vulnerable plugins and could lead to more critical vulnerabilities like RCE.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-285: Improper Authorization
Captchinoo, admin login page protection with Google recaptcha <= 2.3 carries this weakness at cp_plugins_do_button_job_later_callback, and reaching it takes a caller who can reach the endpoint. Improper authorization means a permission check exists but does not cover the case being exercised, so a caller who is allowed to do one thing is allowed to do a neighbouring thing as well.
A lower-privileged account performs an action reserved for a higher one, which on a multi-author or membership site means an ordinary user reaching administrative behaviour. For Captchinoo, admin login page protection with Google recaptcha the fix is 2.4: builds <= 2.3 are affected, anything from 2.4 onward is not.
Remediation
Update to version 2.4, or a newer patched version
How does WordSec protect against this?
Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Captchinoo, admin login page protection with Google recaptcha 2.4 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
Related records
Other vulnerabilities in Captchinoo, admin login page protection with Google recaptcha
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