CVE-2022-25845 in Communications Cloud Native Core Unified Data Repository
Summary
by MITRE • 06/11/2022
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).
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Analysis
by VulDB Data Team • 08/07/2022
The vulnerability identified as CVE-2022-25845 affects the Alibaba fastjson library version 1.2.83 and earlier, representing a critical deserialization flaw that enables remote code execution under specific conditions. This vulnerability resides within the library's handling of untrusted data during the deserialization process, where the default autoType restrictions can be bypassed to execute arbitrary code on the target system. The flaw specifically impacts applications that utilize fastjson for processing JSON data from untrusted sources, creating a significant attack surface for malicious actors seeking to compromise systems. The vulnerability is categorized under CWE-502, Deserialization of Untrusted Data, which is a well-documented weakness in software security that has been exploited in numerous high-profile attacks.
The technical implementation of this vulnerability exploits the library's type handling mechanisms, where attackers can craft malicious JSON payloads that bypass the built-in security measures designed to prevent automatic type resolution. This bypass occurs when the application processes JSON data that contains type information in a way that allows the deserialization engine to execute arbitrary code. The vulnerability is particularly dangerous because it can be exploited remotely without requiring authentication, making it a prime target for automated attacks. The attack vector typically involves sending specially crafted JSON data to an application that uses fastjson for deserialization, which then processes this data and executes the malicious payload.
The operational impact of this vulnerability extends beyond simple remote code execution, as it can lead to complete system compromise and data exfiltration. Attackers can leverage this vulnerability to gain persistent access to affected systems, establish command and control channels, and potentially move laterally within network environments. The vulnerability affects a wide range of applications that depend on fastjson for JSON processing, including web applications, APIs, and backend services. Organizations using vulnerable versions of fastjson may experience unauthorized access to sensitive data, system integrity compromise, and potential regulatory violations due to data breaches. The attack can result in significant financial losses, reputation damage, and compliance violations, particularly for organizations in regulated industries.
Mitigation strategies for this vulnerability include immediate upgrading to fastjson version 1.2.83 or later, which contains the necessary security patches to address the bypass mechanism. When upgrading is not immediately feasible, organizations can implement the safeMode configuration option as a temporary workaround, which restricts the deserialization process and prevents the execution of dangerous types. Additional protective measures include implementing network segmentation, monitoring for suspicious deserialization activities, and conducting thorough code reviews to identify all instances where fastjson is used. Security professionals should also consider implementing web application firewalls and intrusion detection systems to detect and block malicious deserialization attempts. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, specifically focusing on the deserialization attack surface and the potential for remote code execution. Organizations should also consider implementing principle of least privilege access controls and regular security assessments to prevent exploitation of similar vulnerabilities in other components of their software stack.