Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [day] [month] [year] [list]
Date: Mon, 28 Mar 2022 11:16:43 +0800
From: Zexuan Luo <>
To: 人间的四月天 <>,,, 
	Apache Security Team <>,
Subject: CVE-2022-25757: Apache APISIX: the body_schema check in
 request-validation plugin can be bypassed

Severity: low


When decoding JSON with duplicate keys, lua-cjson will choose the last
occurred value as the result. By passing a JSON with a duplicate key,
the attacker can bypass the body_schema validation in the
request-validation plugin. For example,
`{"string_payload":"bad","string_payload":"good"}` can be used to hide
the "bad" input.

Systems satisfy three conditions below are affected by this attack:
1. use body_schema validation in the request-validation plugin
2. upstream application uses a special JSON library that chooses the
first occurred value, like jsoniter or gojay
3. upstream application does not validate the input anymore.

The fix in APISIX is to re-encode the validated JSON input back into
the request body at the side of APISIX.


1. upgrade APISIX to 2.13.0 if you need to use the body_schema
validation in the request-validation plugin
2. add additional validation in the application code, embrace
defensive programming


Thanks for Guangli Dong from

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.