CVE-2017-12980 in DokuWiki
Summary
by MITRE
DokuWiki through 2017-02-19c has stored XSS when rendering a malicious RSS or Atom feed, in /inc/parser/xhtml.php. An attacker can create or edit a wiki that uses RSS or Atom data from an attacker-controlled server to trigger JavaScript execution. The JavaScript can be in an author field, as demonstrated by the dc:creator element.
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Analysis
by VulDB Data Team • 12/16/2022
The vulnerability identified as CVE-2017-12980 represents a critical stored cross-site scripting flaw in DokuWiki versions prior to 2017-02-19c, specifically affecting the XHTML parser component located at /inc/parser/xhtml.php. This vulnerability arises from insufficient input sanitization when processing external RSS or Atom feed data, creating a persistent XSS attack vector that can be exploited by remote attackers. The flaw allows malicious actors to inject arbitrary JavaScript code into wiki pages through the author fields of syndicated content, particularly targeting the dc:creator element as demonstrated in exploitation scenarios.
The technical implementation of this vulnerability stems from the improper handling of user-controllable data within the feed parsing logic. When DokuWiki processes RSS or Atom feeds, it fails to adequately sanitize or escape content from external sources, particularly author information contained in metadata fields. The XSS occurs during the rendering phase when the parsed feed data is converted to XHTML format, allowing malicious JavaScript code embedded in the dc:creator field or similar author metadata to be executed within the context of authenticated users' browsers. This stored nature means the malicious payload persists in the wiki database and executes every time the affected page is loaded, making it particularly dangerous for collaborative environments where multiple users may access compromised content.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities including session hijacking, credential theft, data exfiltration, and privilege escalation within the wiki environment. Attackers can leverage this vulnerability to gain unauthorized access to user accounts, modify wiki content, or establish persistent backdoors through the compromised system. The vulnerability affects all users who have access to wiki pages that display external feed data, potentially compromising entire wiki installations if administrators do not properly validate feed sources. The stored nature of the vulnerability means that even users who do not directly interact with the malicious feed content can be affected when they view pages containing the compromised data, creating a widespread impact across the wiki community.
Mitigation strategies for CVE-2017-12980 should prioritize immediate patching of affected DokuWiki installations to version 2017-02-19c or later, which includes proper input sanitization and output escaping mechanisms for feed data. Organizations should implement strict feed validation policies, limiting the sources of external content and requiring manual approval of all feed integrations. Network-level controls such as web application firewalls and content filtering systems can provide additional protection by blocking suspicious feed data patterns. Security teams should conduct thorough audits of existing wiki content to identify any previously injected malicious code and implement regular monitoring for unauthorized feed modifications. The vulnerability aligns with CWE-79 Cross-site Scripting and maps to ATT&CK technique T1059.007 Command and Scripting Interpreter: JavaScript, demonstrating how attackers can leverage web application vulnerabilities to execute malicious code within user browsers. Additionally, this vulnerability reflects the broader category of insecure data handling practices that can lead to persistent security issues in content management systems, emphasizing the importance of robust input validation and output encoding in web applications.