CVE-2022-25757
By passing a JSON with a duplicate key, the attacker can bypass the body_schema validation in the request-validation plugin.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.48%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.48% probability · 84th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- apache/apisix
- Source
- security@apache.org
References
- http://www.openwall.com/lists/oss-security/2022/03/28/2Mailing List, Third Party Advisory
- https://lists.apache.org/thread/03vd2j81krxmpz6xo8p1dl642flpo6fvMailing List, Vendor Advisory
- http://www.openwall.com/lists/oss-security/2022/03/28/2Mailing List, Third Party Advisory
- https://lists.apache.org/thread/03vd2j81krxmpz6xo8p1dl642flpo6fvMailing List, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.