CVE-2023-27531 in Kredis Gem
Summary
by MITRE • 01/09/2025
There is a deserialization of untrusted data vulnerability in the Kredis JSON deserialization code
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Analysis
by VulDB Data Team • 01/10/2025
The vulnerability identified as CVE-2023-27531 represents a critical deserialization flaw within the Kredis library's JSON processing functionality. This issue arises when the system processes untrusted data through its deserialization mechanisms, creating a potential attack vector for malicious actors to exploit. The vulnerability specifically targets the Kredis library which is commonly used in ruby applications for redis operations and data serialization. The flaw manifests when applications using Kredis attempt to deserialize JSON data from external sources without proper validation or sanitization measures. This type of vulnerability falls under the broader category of insecure deserialization as defined by CWE-502, which occurs when applications deserialize untrusted data without adequate security controls. The vulnerability is particularly concerning because it can be exploited to execute arbitrary code on the target system, potentially leading to complete system compromise.
The technical implementation of this vulnerability stems from inadequate input validation within the Kredis JSON deserialization code. When the library processes incoming JSON data, it fails to properly verify the authenticity and safety of the serialized objects before attempting to deserialize them. This lack of validation allows attackers to craft malicious payloads that, when processed by the vulnerable deserialization logic, can trigger unintended behavior. The flaw typically occurs in the way the library handles object reconstruction during the deserialization process, where it may execute methods or constructors that are part of the serialized data. Attackers can leverage this by creating specially crafted JSON objects that, when deserialized, will execute malicious code or trigger specific system behaviors. This vulnerability aligns with ATT&CK technique T1203 which involves gaining access to systems through exploitation of deserialization vulnerabilities.
The operational impact of CVE-2023-27531 extends beyond simple data corruption or service disruption. An attacker who successfully exploits this vulnerability can achieve arbitrary code execution on the affected system, potentially leading to complete compromise of the application environment. The vulnerability affects systems that rely on Kredis for redis operations and data handling, making it particularly dangerous in web applications, microservices architectures, and distributed systems where redis is commonly used for caching, session management, and inter-process communication. The exploitation of this vulnerability could result in unauthorized data access, data modification, privilege escalation, and persistence mechanisms being established within the target environment. Organizations using applications that depend on Kredis are at risk of experiencing significant security breaches, especially if they process untrusted data from external sources or user inputs.
Mitigation strategies for CVE-2023-27531 should focus on immediate remediation through patching the affected Kredis library to version that addresses the deserialization vulnerability. Organizations must also implement proper input validation and sanitization measures before any deserialization occurs, ensuring that all external data is properly verified and authenticated. The implementation of secure deserialization practices including the use of allowlists for permitted classes, disabling dangerous deserialization features, and employing alternative serialization formats that are less prone to exploitation should be considered. Additionally, network segmentation and monitoring should be enhanced to detect potential exploitation attempts. Organizations should conduct thorough vulnerability assessments to identify all systems using affected versions of Kredis and ensure that proper security controls are in place to prevent exploitation. The remediation process should also include comprehensive testing to verify that the patch does not introduce compatibility issues with existing application functionality while maintaining the security improvements.