CVE-2023-3374 in Bookreen
Summary
by MITRE • 09/05/2023
Incomplete List of Disallowed Inputs vulnerability in Unisign Bookreen allows Privilege Escalation.This issue affects Bookreen: before 3.0.0.
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Analysis
by VulDB Data Team • 05/22/2026
The vulnerability identified as CVE-2023-3374 represents a critical security flaw in the Bookreen application affecting versions prior to 3.0.0. This issue manifests as an incomplete list of disallowed inputs, creating a pathway for unauthorized privilege escalation attacks. The vulnerability stems from insufficient input validation mechanisms within the application's security framework, allowing malicious actors to bypass intended access controls and elevate their privileges within the system. Such a flaw fundamentally undermines the application's security model and creates significant risks for organizations relying on Bookreen for their operational needs.
The technical nature of this vulnerability aligns with CWE-20, which describes "Improper Input Validation" as a core weakness that enables various attack vectors including privilege escalation. The flaw occurs when the application fails to maintain a comprehensive blacklist of dangerous input patterns, allowing crafted malicious inputs to pass through validation checks. This incomplete filtering mechanism creates a security gap where attackers can exploit the system's trust in seemingly benign inputs while simultaneously bypassing critical access control measures. The vulnerability specifically targets the privilege escalation aspect, meaning that an attacker with minimal initial access could potentially gain administrative or elevated privileges within the Bookreen environment.
Operationally, this vulnerability poses severe risks to organizations using Bookreen, particularly those handling sensitive data or requiring strict access controls. The privilege escalation capability means that an attacker could potentially gain unauthorized access to confidential information, modify system configurations, or even take full control of the application environment. The impact extends beyond immediate data compromise to include potential lateral movement within networks where Bookreen might be integrated with other systems. Organizations may face regulatory compliance issues if sensitive data is accessed or modified without proper authorization, especially in industries governed by standards such as gdpr, hipaa, or pci dss. The vulnerability's presence in pre-3.0.0 versions indicates that this was likely a known issue that required a major version update to address properly.
The recommended mitigation strategy involves immediate deployment of the patched version 3.0.0 or later, which should contain comprehensive input validation mechanisms and proper disallowed input handling. Organizations should also implement additional security controls including regular input validation testing, monitoring for unusual privilege escalation attempts, and maintaining up-to-date security patches across all systems. Security teams should conduct thorough assessments of their Bookreen implementations to identify any potential exploitation attempts and ensure proper access controls are in place. This vulnerability demonstrates the critical importance of maintaining robust input validation processes and the necessity of regular security updates to prevent exploitation of known vulnerabilities. The issue also highlights the importance of following secure coding practices that align with industry standards such as those outlined in the mitre attack framework, where such input validation failures often serve as initial access vectors for more sophisticated attacks. Organizations should consider implementing automated security testing tools that can detect similar input validation issues in their applications and establish processes for continuous security monitoring to identify and respond to potential exploitation attempts.