CVE-2023-46802 in e-Tax software
Summary
by MITRE • 11/06/2023
e-Tax software Version3.0.10 and earlier improperly restricts XML external entity references (XXE) due to the configuration of the embedded XML parser. By processing a specially crafted XML file, arbitrary files on the system may be read by an attacker.
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Analysis
by VulDB Data Team • 10/29/2024
The vulnerability identified as CVE-2023-46802 affects e-Tax software versions 3.0.10 and earlier, representing a critical XML external entity processing flaw that exposes systems to unauthorized file access. This issue stems from improper configuration of the embedded XML parser within the software, creating a pathway for malicious actors to exploit the system through carefully crafted XML input files. The vulnerability classifies under CWE-611, which specifically addresses improper restriction of XML external entities, making it a well-documented weakness in XML processing implementations. The flaw allows attackers to leverage XML parsing mechanisms to read arbitrary files from the target system, potentially exposing sensitive data and system information that should remain protected.
The technical exploitation of this XXE vulnerability occurs when the e-Tax software processes XML input without proper validation or sanitization of external entity references. When an attacker submits a malicious XML file containing references to external entities, the improperly configured parser resolves these references and attempts to access the specified resources on the local filesystem. This process can be extended to include file protocol references, allowing attackers to read system files, configuration data, or other sensitive information stored on the server. The vulnerability essentially bypasses normal access controls by leveraging the XML parser's inherent capabilities to resolve external references, which should have been properly restricted in a secure implementation.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with potential access to sensitive tax-related data, system configuration files, and possibly credentials stored in accessible locations. Organizations using affected e-Tax software versions face significant risks including data breaches, compliance violations, and potential system compromise. The vulnerability aligns with ATT&CK technique T1566.001, which covers the use of malicious external entities in XML processing, making it particularly dangerous in environments where tax software handles confidential financial information. Attackers could potentially escalate their access to other system components by first reading configuration files or database connection details that might be stored in accessible locations.
Security mitigations for this vulnerability should focus on immediate remediation through software updates to versions that properly configure XML parsers to disable external entity resolution. Organizations must ensure that XML parsers are configured with secure defaults that prevent loading external entities, particularly when processing untrusted input. The implementation of input validation and sanitization measures, combined with proper XML schema validation, can help prevent exploitation attempts. Additionally, network segmentation and access controls should be implemented to limit the potential impact of successful exploitation attempts, while regular security assessments should verify that XML processing components are properly configured according to security best practices. The vulnerability demonstrates the critical importance of secure XML processing configurations and the potential for seemingly minor parser settings to create significant security risks in enterprise applications.