CVE-2018-15474 in DokuWiki
Summary
by MITRE
** DISPUTED ** CSV Injection (aka Excel Macro Injection or Formula Injection) in /lib/plugins/usermanager/admin.php in DokuWiki 2018-04-22a and earlier allows remote attackers to exfiltrate sensitive data and to execute arbitrary code via a value that is mishandled in a CSV export. NOTE: the vendor has stated "this is not a security problem in DokuWiki."
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Analysis
by VulDB Data Team • 08/05/2024
The vulnerability identified as CVE-2018-15474 represents a disputed csv injection flaw within the usermanager plugin of DokuWiki version 2018-04-22a and earlier. This issue specifically affects the /lib/plugins/usermanager/admin.php file where malicious input can be exploited during csv export operations. The vulnerability stems from improper handling of user-supplied data within the csv export functionality, creating potential attack vectors that could allow remote code execution and data exfiltration. While the vendor has officially disputed the security implications of this issue, the potential for exploitation remains a concern for system administrators and security professionals managing DokuWiki installations.
The technical implementation of this vulnerability involves the manipulation of csv export functionality to inject malicious formulas or commands that execute within the context of spreadsheet applications like Microsoft Excel. When users download csv files containing specially crafted input, the spreadsheet application may interpret certain prefixes such as equals signs, plus signs, or other formula indicators as executable commands. This behavior aligns with common csv injection attack patterns documented in cybersecurity literature and represents a variant of formula injection techniques that have been widely exploited in various web applications and content management systems. The flaw operates at the data handling level where user input is not properly sanitized before being included in csv output, creating opportunities for attackers to embed malicious payloads within seemingly benign data exports.
The operational impact of this vulnerability extends beyond simple data exfiltration to encompass potential remote code execution capabilities within the target environment. Attackers could leverage this flaw to execute arbitrary commands on systems where the exported csv files are opened, particularly when users access these files in spreadsheet applications that interpret formulaic content. The security implications become more severe when considering that many organizations rely on csv exports for data management and reporting purposes, making these files potential attack vectors for lateral movement and privilege escalation. This vulnerability particularly affects environments where users frequently interact with exported data and where spreadsheet applications are used to process the downloaded files, creating multiple attack surfaces for exploitation.
Organizations should implement comprehensive mitigation strategies that address both the immediate technical flaw and broader security practices surrounding data export operations. The recommended approach involves thorough input validation and sanitization of user data before inclusion in csv exports, particularly focusing on the removal or encoding of potentially dangerous characters that could trigger formula execution. Security teams should also consider implementing network-level controls and user education programs to reduce the risk of accidental exploitation through social engineering attacks that might encourage users to open suspicious csv files. Additionally, regular security assessments of web applications should include evaluation of data export functionality to identify similar vulnerabilities that could be exploited through various injection techniques. This vulnerability demonstrates the importance of considering the complete data lifecycle in security design, including how data is exported and consumed by end users. The incident also highlights the necessity for security vendors and developers to maintain clear communication regarding the true security implications of reported vulnerabilities, as vendor statements may not always align with the actual risks faced by users in diverse operational environments.
This vulnerability type relates to CWE-1236 which defines improper neutralization of special elements used in a csv file, and can be mapped to ATT&CK techniques including T1059 for command and scripting interpreter and T1074 for data staging, representing the complete attack chain from initial exploitation to data exfiltration. The security community should remain vigilant about similar injection vulnerabilities in data export functions across various applications, as these often represent overlooked attack surfaces that can be leveraged for significant security breaches.