CVE-2021-43557

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.

• CWE-77

• http://www.openwall.com/lists/oss-security/2021/11/22/1Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2021/11/22/2Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2021/11/23/1Exploit, Mailing List, Third Party Advisory
• https://lists.apache.org/thread/18jyd458ptocr31rnkjs71w4h366mv7hExploit, Mailing List, Vendor Advisory
• http://www.openwall.com/lists/oss-security/2021/11/22/1Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2021/11/22/2Mailing List, Third Party Advisory
• http://www.openwall.com/lists/oss-security/2021/11/23/1Exploit, Mailing List, Third Party Advisory
• https://lists.apache.org/thread/18jyd458ptocr31rnkjs71w4h366mv7hExploit, Mailing List, Vendor Advisory

Published

Nov 22, 2021

Last Modified

Jun 17, 2026

Status

Modified

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