CVE-2021-43557: Apache APISIX

High severity, CVSS 7.5. EPSS: 12.9% chance of exploitation in the next 30 days.

The uri-block plugin in Apache APISIX before 2.10.2 uses $request_uri without verification. The $request_uri is the full original request URI without normalization. This makes it possible to construct a URI to bypass the block list on some occasions. For instance, when the block list contains "^/internal/", a URI like `//internal/` can be used to bypass it. Some other plugins also have the same issue. And it may affect the developer's custom plugin.

Affected products

• Apache APISIX: before 2.10.2 (fixed in 2.10.2)

Published 2021-11-22. Last modified 2026-06-17.