CVE-2015-8509 in Bugzilla
Summary
by MITRE
Template.pm in Bugzilla 2.x, 3.x, and 4.x before 4.2.16, 4.3.x and 4.4.x before 4.4.11, and 4.5.x and 5.0.x before 5.0.2 does not properly construct CSV files, which allows remote attackers to obtain sensitive information by leveraging a web browser that interprets CSV data as JavaScript code.
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Analysis
by VulDB Data Team • 07/02/2022
The vulnerability identified as CVE-2015-8509 resides within the Template.pm component of Bugzilla, a widely-used web-based bug tracking system that has been integral to software development workflows since its inception. This flaw affects multiple versions of Bugzilla spanning from 2.x through 5.0.x, specifically before the security patches released in versions 4.2.16, 4.4.11, and 5.0.2 respectively. The vulnerability stems from improper handling of CSV file construction within the application's template processing system, creating a critical security gap that could be exploited by remote attackers. The flaw represents a classic case of insecure data handling where the application fails to properly sanitize or escape data that is intended for CSV output, potentially allowing attackers to inject malicious content that could be interpreted by web browsers.
The technical mechanism of this vulnerability involves the way Bugzilla constructs CSV files for export functionality, where the application does not adequately escape or sanitize special characters that could be interpreted by web browsers as executable code. When users download bug reports or other data in CSV format, the Template.pm module fails to properly handle certain characters that could trigger JavaScript execution within browser contexts. This occurs because CSV files, when opened in web browsers, can be interpreted as having executable content, particularly when the file contains characters that resemble JavaScript code or HTML tags. The vulnerability is particularly dangerous because it leverages the inherent behavior of web browsers to interpret CSV content, where certain sequences can be interpreted as script tags or other executable constructs. This misconfiguration allows attackers to craft malicious CSV files that, when opened in a browser, can execute arbitrary JavaScript code within the context of the user's session.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential remote code execution capabilities within the context of the user's browser session. Attackers can exploit this flaw by crafting malicious CSV files that contain JavaScript code within the exported data, which then executes when users open the files in their browsers. This could lead to session hijacking, credential theft, or the execution of malicious payloads that could compromise the user's browser environment. The vulnerability is particularly concerning because it affects multiple major versions of Bugzilla, meaning that organizations with legacy installations could be at risk for extended periods. The flaw also demonstrates how seemingly innocuous data export functionality can become a vector for sophisticated attacks, as it exploits the trust users place in exported data files. From a cybersecurity perspective, this vulnerability aligns with CWE-113, which addresses improper neutralization of data within the context of a different system, and represents a form of cross-site scripting that occurs through CSV data manipulation rather than traditional web input vectors.
Organizations using affected versions of Bugzilla should immediately implement mitigations including updating to patched versions, implementing proper input validation for CSV export functionality, and educating users about the risks of opening downloaded CSV files in web browsers. The recommended remediation strategy involves applying the vendor patches that address the CSV construction logic in Template.pm, ensuring that special characters are properly escaped or encoded when generating CSV files. Additionally, organizations should consider implementing content security policies that prevent the execution of JavaScript from CSV files, and establish procedures for validating downloaded files before opening them. From an ATT&CK framework perspective, this vulnerability maps to techniques involving malicious file execution and credential access through web-based attacks, specifically leveraging the T1059.007 sub-technique for JavaScript execution within browser contexts. The vulnerability also demonstrates how application-level flaws in data processing can create persistent security risks that require comprehensive remediation rather than simple patch application, emphasizing the importance of secure coding practices in web application development and the need for proper data sanitization throughout the application lifecycle.