Vulnerability · Published Mar 28, 2022 · Assigned by apache

CVE-2022-25757Apache APISIX: the body_schema check in request-validation plugin can be bypassed

Critical 9.8

In plain English

A critical-severity improper input validation in Apache APISIX from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.5% (higher than 85% of all known vulnerabilities).

Severity (CVSS NVD)9.8Critical

Exploit odds (30 days)2.5%top 15.3% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

In Apache APISIX before 2.13.0, 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. Improper Input Validation vulnerability in __COMPONENT__ of Apache APISIX allows an attacker to __IMPACT__. This issue affects Apache APISIX Apache APISIX version 2.12.1 and prior versions.

Affected products (as reported)

Vendor	Product	Versions
Apache Software Foundation	Apache APISIX	Apache APISIX – through 2.12.1

Weakness: CWE-20

References

https://lists.apache.org/thread/03vd2j81krxmpz6xo8p1dl642flpo6fv x_refsource_MISC
[oss-security] 20220328 CVE-2022-25757: Apache APISIX: the body_schema check in request-validation plugin can be bypassed mailing-list, x_refsource_MLIST