CVE-2021-43557: Path traversal in request_uri variable
First published: Mon Nov 22 2021(Updated: )
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.
Credit: security@apache.org security@apache.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Apache APISIX | <2.10.2 | |
| <2.10.2 |
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Reference Links
Frequently Asked Questions
What is CVE-2021-43557?
CVE-2021-43557 is a vulnerability in Apache APISIX before version 2.10.2 that allows bypassing the block list using an unverified $request_uri.
How severe is CVE-2021-43557?
CVE-2021-43557 has a severity rating of 7.5 (High).
Which software versions are affected by CVE-2021-43557?
Apache APISIX versions up to and excluding 2.10.2 are affected by CVE-2021-43557.
How can I fix CVE-2021-43557?
To fix CVE-2021-43557, upgrade Apache APISIX to version 2.10.2 or later.
What is the CWE ID for CVE-2021-43557?
The CWE ID for CVE-2021-43557 is CWE-77.
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