CVE-2024-39684 in RapidJSON
Summary
by MITRE • 07/09/2024
Tencent RapidJSON is vulnerable to privilege escalation due to an integer overflow in the `GenericReader::ParseNumber()` function of `include/rapidjson/reader.h` when parsing JSON text from a stream. An attacker needs to send the victim a crafted file which needs to be opened; this triggers the integer overflow vulnerability (when the file is parsed), leading to elevation of privilege.
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Analysis
by VulDB Data Team • 05/05/2026
The vulnerability identified as CVE-2024-39684 affects Tencent RapidJSON, a widely used C++ JSON parsing library that is integral to numerous applications across various platforms. This security flaw resides within the `GenericReader::ParseNumber()` function located in the `include/rapidjson/reader.h` header file, representing a critical weakness that can be exploited to achieve unauthorized privilege escalation. The vulnerability stems from improper handling of integer overflow conditions during the parsing of numeric values from JSON streams, creating a potential attack vector that can be leveraged by malicious actors to compromise system integrity.
The technical implementation of this vulnerability occurs when RapidJSON processes JSON text from a stream, specifically during the number parsing phase. When a crafted JSON payload containing maliciously constructed numeric values is processed, the integer overflow condition manifests within the parsing logic. This overflow can cause the parser to behave unpredictably, potentially leading to memory corruption or other exploitable conditions. The vulnerability requires a specific attack scenario where an attacker must deliver a crafted file to a victim, who must then open this file, triggering the parsing process that exposes the integer overflow. This delivery mechanism aligns with common social engineering tactics and highlights the importance of input validation in JSON processing libraries.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially enable complete system compromise. When successful, the integer overflow can allow attackers to execute arbitrary code with elevated privileges, potentially leading to full system control. The vulnerability affects any application that relies on RapidJSON for JSON parsing, including web applications, mobile apps, and server-side systems. Given RapidJSON's widespread adoption across different software ecosystems, the potential attack surface is extensive, making this vulnerability particularly concerning for security professionals. The attack vector requires user interaction through file opening, which makes it more difficult to exploit automatically but still presents a significant risk in environments where users frequently open external files.
Mitigation strategies for CVE-2024-39684 should prioritize immediate patching of affected RapidJSON versions, as this represents the most effective defense against the integer overflow condition. Organizations should implement comprehensive input validation mechanisms that can detect and reject malformed JSON data before it reaches the RapidJSON parser. Additionally, runtime protections such as address space layout randomization and stack canaries can provide additional layers of defense against exploitation attempts. Security teams should monitor for any attempts to exploit this vulnerability through network traffic analysis or file access patterns, particularly in environments where users might encounter untrusted JSON content. The vulnerability demonstrates the critical importance of rigorous input validation and proper integer handling in parsing libraries, as highlighted by CWE-190, which addresses integer overflow conditions. This issue also aligns with ATT&CK technique T1059, which covers command and scripting interpreter usage, as successful exploitation could enable attackers to execute arbitrary commands with elevated privileges. Organizations should also consider implementing application whitelisting policies and restricting user access to potentially dangerous file types to reduce the risk of successful exploitation.