Remote Code Execution in fastjson 1.2.68–1.2.83

A remote code execution (RCE) vulnerability exists in fastjson 1.2.68 through 1.2.83. This vulnerability is exploitable under fastjson's stock default configuration — no AutoType enablement required, no classpath gadget required.

fastjson: From CVEorg collector

Fastjson before 1.2.48 mishandles autoType because, when an @type key is in a JSON document, and the value of that key is the name of a Java class, there may be calls to certain public methods of that class. Depending on the behavior of those methods, there may be JNDI injection with an attacker-supplied payload located elsewhere in that JSON document. This was exploited in the wild in 2023 through 2025. NOTE: this issue exists because of an incomplete fix for CVE-2017-18349. Also, a later bypass is covered by CVE-2022-25845.

ktg-mes before commit a484f96 (2025-07-03) has a fastjson deserialization vulnerability. This is because it uses a vulnerable version of fastjson and deserializes unsafe input data.

Deserialization of Untrusted Data

The package com.alibaba:fastjson before 1.2.83 are vulnerable to Deserialization of Untrusted Data by bypassing the default autoType shutdown restrictions, which is possible under certain conditions. Exploiting this vulnerability allows attacking remote servers. Workaround: If upgrading is not possible, you can enable [safeMode](https://github.com/alibaba/fastjson/wiki/fastjson_safemode).

parseObject in Fastjson before 1.2.25, as used in FastjsonEngine in Pippo 1.11.0 and other products, allows remote attackers to execute arbitrary code via a crafted JSON request, as demonstrated by a crafted rmi:// URI in the dataSourceName field of HTTP POST data to the Pippo /json URI, which is mishandled in AjaxApplication.java.