CVE-2025-6566 in Oat++
Summary
by MITRE • 06/24/2025
A vulnerability was found in oatpp Oat++ up to 1.3.1. It has been declared as critical. This vulnerability affects the function deserializeArray of the file src/oatpp/json/Deserializer.cpp. The manipulation leads to stack-based buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 06/25/2025
The vulnerability identified as CVE-2025-6566 represents a critical stack-based buffer overflow within the oatpp Oat++ framework version 1.3.1 and earlier. This flaw resides in the deserializeArray function located within the src/oatpp/json/Deserializer.cpp file, making it a core component of the JSON deserialization process that applications using this framework rely upon for processing incoming data. The vulnerability's classification as critical stems from its potential to enable remote code execution when exploited, particularly given that the exploit has been publicly disclosed and is considered readily available for malicious actors.
The technical nature of this flaw involves improper bounds checking during the deserialization of array data structures, where the application fails to validate the size of incoming data against the allocated stack buffer space. When an attacker crafts malicious JSON input containing oversized arrays, the deserializeArray function attempts to copy data beyond the confines of the stack-allocated buffer, resulting in a buffer overflow condition. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is a well-documented weakness in software security that enables attackers to overwrite adjacent memory locations and potentially execute arbitrary code.
The operational impact of this vulnerability extends beyond simple data corruption, as it provides a remote attack surface that can be exploited without requiring authentication or specialized privileges. The attack vector is particularly concerning because it can be initiated through network-based JSON requests that applications using oatpp might receive from external sources, including web services, API endpoints, or any interface that processes JSON data through the affected deserialization function. This makes the vulnerability highly relevant to web applications, microservices, and API gateways that utilize the oatpp framework for handling JSON-based communication protocols.
Security practitioners should consider this vulnerability in the context of the MITRE ATT&CK framework, specifically under the T1203 Exploitation for Client Execution and T1059 Command and Scripting Interpreter techniques, as the buffer overflow can potentially be leveraged to execute arbitrary commands on the affected system. The public disclosure of the exploit means that threat actors can readily develop automated tools to scan for vulnerable systems and deploy attacks without requiring advanced technical knowledge. Organizations using oatpp versions up to 1.3.1 must urgently implement mitigations including immediate patching to version 1.3.2 or later, implementing input validation controls, and deploying network segmentation to limit exposure of affected services to untrusted networks.
The recommended mitigation strategy involves upgrading to the patched version of oatpp where the buffer overflow has been addressed through proper bounds checking and memory management practices. Additionally, implementing defensive programming techniques such as input sanitization, using static analysis tools to identify similar patterns in custom code, and establishing runtime protections like stack canaries or address space layout randomization can provide additional layers of defense. Organizations should also conduct comprehensive vulnerability assessments to identify all applications and services using affected versions of the framework, and implement monitoring solutions to detect potential exploitation attempts in their production environments.