CVE-2022-0717 in mruby
Summary
by MITRE • 02/23/2022
Out-of-bounds Read in GitHub repository mruby/mruby prior to 3.2.
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Analysis
by VulDB Data Team • 08/28/2025
The vulnerability CVE-2022-0717 represents a critical out-of-bounds read flaw discovered in the mruby scripting engine repository prior to version 3.2. This issue affects the mruby implementation which is a lightweight ruby implementation designed for embedding within applications. The vulnerability manifests when the mruby interpreter processes certain input sequences that trigger improper bounds checking during array or string operations. The flaw exists in the core interpreter logic where memory access validation is insufficient, allowing attackers to read memory locations beyond the intended array boundaries. This type of vulnerability falls under the CWE-125 category of out-of-bounds read, which is classified as a memory safety issue that can lead to information disclosure or potentially more severe exploitation vectors.
The technical execution of this vulnerability requires crafting specific input that causes the mruby interpreter to access memory locations outside of allocated buffers. When the interpreter encounters malformed array indexing or string operations, it fails to properly validate the bounds of memory access operations. This allows an attacker to potentially read sensitive data from adjacent memory locations including stack contents, heap data, or other process memory regions. The vulnerability is particularly concerning because mruby is often embedded in applications where it serves as a scripting layer, making the attack surface broader than just the interpreter itself. The flaw demonstrates poor input validation practices and inadequate memory management checks within the interpreter's core processing functions.
Operationally, this vulnerability poses significant risks to systems that utilize mruby for scripting purposes, particularly in web applications, embedded systems, or any environment where user-supplied input is processed through the mruby interpreter. An attacker could potentially exploit this to extract sensitive information from the process memory, including cryptographic keys, session tokens, or other confidential data that might be stored in adjacent memory locations. The impact extends beyond simple information disclosure as this vulnerability could serve as a stepping stone for more sophisticated attacks, potentially leading to privilege escalation or remote code execution depending on the specific memory layout and application context. The vulnerability is especially dangerous in environments where mruby is used for processing untrusted input without proper sanitization.
Mitigation strategies for CVE-2022-0717 primarily involve upgrading to mruby version 3.2 or later where the bounds checking has been properly implemented. Organizations should conduct thorough vulnerability assessments to identify all systems utilizing mruby and ensure proper patching of affected versions. Additionally, implementing input validation measures and sandboxing techniques can provide additional defense-in-depth layers. Security teams should monitor for any signs of exploitation attempts and consider implementing runtime protections such as address space layout randomization and stack canaries. The vulnerability highlights the importance of proper memory safety practices and adherence to secure coding guidelines as outlined in the software security standards that emphasize the need for comprehensive bounds checking and memory access validation in interpreted languages. This vulnerability also aligns with ATT&CK technique T1059.007 for script-based attacks, where adversaries leverage scripting engines to execute malicious code or extract information from target systems.