CVE-2016-4561 in Ikiwiki
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the cgierror function in CGI.pm in ikiwiki before 3.20160506 might allow remote attackers to inject arbitrary web script or HTML via unspecified vectors involving an error message.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 08/18/2022
The vulnerability identified as CVE-2016-4561 represents a cross-site scripting flaw within the ikiwiki content management system's CGI.pm module. This issue affects versions prior to 3.20160506 and specifically targets the cgierror function which handles error message processing. The vulnerability arises from insufficient input validation and output encoding mechanisms when processing error conditions within the web application framework. Attackers can exploit this weakness to inject malicious scripts or HTML content through unspecified vectors that involve error message handling, potentially compromising user sessions and data integrity.
The technical implementation of this vulnerability stems from improper sanitization of user-supplied data within the cgierror function of CGI.pm. When ikiwiki encounters an error condition, it generates error messages that should be properly escaped to prevent execution of malicious code. However, the vulnerability allows attackers to inject arbitrary web scripts or HTML content that gets executed in the context of other users' browsers. This occurs because the error handling mechanism fails to adequately encode or filter potentially malicious input that may be present in error messages, creating an XSS attack surface that can be exploited by remote adversaries without requiring authentication or privileged access.
From an operational impact perspective, this vulnerability poses significant risks to ikiwiki installations that process user-generated content or handle error conditions involving external inputs. An attacker could leverage this vulnerability to steal session cookies, redirect users to malicious websites, or execute arbitrary code within the victim's browser context. The attack vector is particularly concerning because it operates through error message handling rather than direct user input, making it harder to detect and prevent through conventional input validation measures. This vulnerability can affect any ikiwiki installation that processes external data or user inputs that may trigger error conditions, potentially compromising the entire web application ecosystem.
Security mitigations for this vulnerability involve immediate upgrading to ikiwiki version 3.20160506 or later, which contains the necessary patches to address the XSS flaw in the cgierror function. Organizations should also implement comprehensive input validation and output encoding mechanisms throughout their web applications, ensuring that all user-supplied data is properly sanitized before being processed or displayed. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting vulnerabilities, and can be mapped to ATT&CK technique T1203, which involves exploitation of web application vulnerabilities. Additional defensive measures include implementing content security policies, regular security audits of web application components, and monitoring for suspicious error message patterns that may indicate exploitation attempts.