CVE-2021-23441 in jsoniter
Summary
by MITRE • 09/19/2021
All versions of package com.jsoniter:jsoniter are vulnerable to Deserialization of Untrusted Data via malicious JSON strings. This may lead to a Denial of Service, and in certain cases, code execution.
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Analysis
by VulDB Data Team • 09/22/2021
The vulnerability identified as CVE-2021-23441 affects the com.jsoniter:jsoniter package, which is a high-performance json library for java applications. This issue represents a critical deserialization flaw that allows attackers to manipulate the parsing process through carefully crafted malicious json strings. The vulnerability stems from insufficient input validation during the deserialization phase, where the library fails to properly sanitize or verify the structure and content of incoming json data before processing it into java objects.
This deserialization vulnerability falls under the common weakness enumeration CWE-502 which specifically addresses the deserialization of untrusted data. The attack vector involves an attacker submitting malicious json payloads that, when processed by the vulnerable jsoniter library, can trigger unintended behavior within the target application. The technical flaw manifests when the library attempts to convert json data into java objects without adequate safeguards against potentially harmful data structures or object types that could be exploited during the deserialization process.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution in certain environments. When exploited, malicious json strings can cause the application to execute arbitrary code on the target system, effectively compromising the entire application stack. The severity of this vulnerability is amplified by the widespread use of jsoniter in enterprise applications and microservices architectures where json parsing is a fundamental operation. Attackers can leverage this vulnerability to gain unauthorized access, escalate privileges, or disrupt service availability across affected systems.
Organizations should immediately update their dependencies to versions that address this vulnerability, typically those containing patches or fixes that implement proper input validation and sanitization during the deserialization process. Additional mitigations include implementing network-level restrictions to limit access to json parsing endpoints, employing application firewalls to filter suspicious json payloads, and conducting thorough code reviews to identify any custom deserialization logic that might be vulnerable. The attack surface can be reduced by limiting the types of objects that can be deserialized and by implementing strict object whitelisting mechanisms. Security teams should also consider monitoring for unusual json parsing patterns and implementing intrusion detection systems that can identify potential exploitation attempts targeting this specific vulnerability.