CVE-2023-46749 is a path traversal vulnerability classified under CWE-22 affecting Apache Shiro, a widely used Java security framework for authentication and authorization. The vulnerability exists in Apache Shiro versions before 1.13.0 and 2.0.0-alpha-4, where improper validation and limitation of pathname inputs allow attackers to manipulate URL paths when path rewriting is enabled. This manipulation can bypass authentication mechanisms, granting unauthorized access to protected resources. The issue stems from insufficient sanitization of semicolon characters and path segments, which can be exploited to traverse directories or alter request handling logic. The vulnerability does not expose confidential data directly nor cause denial of service but compromises the integrity of authentication controls, enabling attackers with network access and low privileges to escalate access without user interaction. The CVSS 3.1 score of 6.5 reflects the medium severity, emphasizing the ease of exploitation and impact on integrity. Mitigation is straightforward: upgrading to Apache Shiro 1.13.0 or 2.0.0-alpha-4 and above addresses the flaw by improving path validation. Alternatively, ensuring the 'blockSemicolon' configuration is enabled (which is the default setting) prevents exploitation by blocking malicious path characters. No known exploits are currently reported in the wild, but the vulnerability's nature warrants proactive remediation. Organizations using Apache Shiro in web applications, particularly those employing path rewriting features, should assess their exposure and apply patches promptly.

For European organizations, this vulnerability poses a significant risk to the integrity of authentication systems in web applications using vulnerable Apache Shiro versions. Successful exploitation allows attackers to bypass authentication controls, potentially leading to unauthorized access to sensitive internal systems, user accounts, or administrative functions. This can result in data manipulation, privilege escalation, and lateral movement within networks. Although confidentiality and availability are not directly impacted, the integrity breach can undermine trust in affected systems and lead to regulatory compliance issues under GDPR if unauthorized access results in data misuse. Sectors with critical infrastructure, finance, healthcare, and government services are particularly vulnerable due to their reliance on secure authentication. The medium severity rating suggests a moderate but actionable threat, emphasizing the need for timely patching to prevent exploitation. The absence of known exploits in the wild reduces immediate risk but does not eliminate the potential for future attacks, especially as threat actors often target widely used frameworks like Apache Shiro.

1. Upgrade Apache Shiro to version 1.13.0 or later, or 2.0.0-alpha-4 or later, as these versions contain fixes that properly limit pathname inputs and prevent path traversal. 2. Verify that the 'blockSemicolon' configuration is enabled in Apache Shiro settings; this blocks semicolon characters in paths that facilitate traversal attacks and is enabled by default in patched versions. 3. Conduct a thorough audit of web application path rewriting rules and ensure they do not inadvertently allow manipulation of request paths. 4. Implement strict input validation and sanitization on all user-supplied URL parameters to prevent injection of malicious path segments. 5. Monitor authentication logs for unusual access patterns or repeated failed attempts that could indicate exploitation attempts. 6. Employ web application firewalls (WAFs) with rules designed to detect and block path traversal payloads targeting Apache Shiro. 7. Educate development and security teams about the risks of path traversal and the importance of secure configuration management. 8. Integrate vulnerability scanning tools that specifically check for outdated Apache Shiro versions and path traversal vulnerabilities in CI/CD pipelines to prevent regression.