Vulnerability · Published Dec 21, 2020 · Assigned by mitre
CVE-2020-35590
Critical 9.8
In plain English
A critical-severity security flaw in the affected software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 4.3% (higher than 91% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official description
LimitLoginAttempts.php in the limit-login-attempts-reloaded plugin before 2.17.4 for WordPress allows a bypass of (per IP address) rate limits because the X-Forwarded-For header can be forged. When the plugin is configured to accept an arbitrary header for the client source IP address, a malicious user is not limited to perform a brute force attack, because the client IP header accepts any arbitrary string. When randomizing the header input, the login count does not ever reach the maximum allowed retries.