CVE-2023-42479 in Biller Direct
Summary
by MITRE • 12/12/2023
An unauthenticated attacker can embed a hidden access to a Biller Direct URL in a frame which, when loaded by the user, will submit a cross-site scripting request to the Biller Direct system. This can result in the disclosure or modification of non-sensitive information.
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Analysis
by VulDB Data Team • 12/12/2023
The vulnerability identified as CVE-2023-42479 represents a significant cross-site scripting flaw within the Biller Direct system that allows unauthenticated attackers to exploit frame-based injection techniques. This security weakness stems from insufficient input validation and output encoding mechanisms within the web application's frame handling functionality. The vulnerability specifically enables attackers to embed malicious Biller Direct URLs within HTML frames, creating a covert channel for executing malicious scripts against unsuspecting users who interact with the compromised content. The flaw operates by leveraging the trust relationship between the victim's browser and the Biller Direct system, allowing attackers to craft malicious payloads that appear legitimate within the frame context.
The technical exploitation of this vulnerability occurs through the manipulation of frame-based URL embedding mechanisms within the Biller Direct application. When a user loads a webpage containing the malicious frame, the embedded Biller Direct URL automatically executes a cross-site scripting request without proper authentication or authorization checks. The vulnerability demonstrates characteristics consistent with CWE-79 - Cross-site Scripting, specifically targeting the frame-based injection vector where attackers can manipulate frame content to execute malicious scripts. This type of attack falls under the ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, as it involves the delivery of malicious content through frame embedding that can be triggered by user interaction.
The operational impact of CVE-2023-42479 extends beyond simple information disclosure, as the vulnerability enables modification of non-sensitive information within the Biller Direct system. While the description mentions non-sensitive data exposure, the potential for information modification creates risks for data integrity and system availability. Attackers could potentially manipulate user data, alter transaction records, or disrupt normal system operations through the executed cross-site scripting payloads. The unauthenticated nature of this vulnerability means that attackers do not require valid credentials or privileged access to exploit the flaw, making it particularly dangerous for systems handling financial or transactional data. The vulnerability could also serve as a stepping stone for more sophisticated attacks, potentially leading to privilege escalation or further system compromise through chained attacks.
Mitigation strategies for CVE-2023-42479 should focus on implementing robust input validation and output encoding mechanisms within the Biller Direct application. Organizations should enforce strict content security policies that prevent unauthorized frame embedding and implement proper frame validation techniques to detect and block malicious frame content. The application should employ proper sanitization of all user-supplied input and ensure that frame content is properly escaped and validated before rendering. Additionally, implementing proper access controls and authentication mechanisms for all system interactions, as recommended by OWASP Top 10 security practices, would significantly reduce the risk of exploitation. Regular security testing including dynamic application security testing and manual penetration testing should be conducted to identify and remediate similar vulnerabilities in the system's frame handling functionality. The implementation of a web application firewall with rules specifically designed to detect and block frame-based XSS attacks would provide an additional layer of protection against this class of vulnerability.