CVE-2020-19000 in Simiki
Summary
by MITRE • 08/28/2021
Cross Site Scripting (XSS) in Simiki v1.6.2.1 and prior allows remote attackers to execute arbitrary code via line 54 of the component 'simiki/blob/master/simiki/generators.py'.
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Analysis
by VulDB Data Team • 09/01/2021
The vulnerability identified as CVE-2020-19000 represents a critical cross site scripting flaw within the Simiki static site generator version 1.6.2.1 and earlier releases. This vulnerability resides in the code generation component where user-supplied input is not properly sanitized before being rendered in the output HTML. The specific issue occurs at line 54 of the simiki/generators.py file, which processes content that should be treated as untrusted data from external sources. The flaw allows remote attackers to inject malicious JavaScript code into the generated web pages, potentially compromising the integrity of the entire site and affecting all users who access the vulnerable content. This type of vulnerability falls under the CWE-79 category for Cross Site Scripting, which is one of the most prevalent and dangerous web application security flaws. The attack vector is particularly concerning because it enables attackers to execute arbitrary code within the context of the victim's browser, potentially leading to session hijacking, data theft, or further exploitation of the compromised system.
The technical implementation of this vulnerability demonstrates a classic failure in input validation and output encoding practices within the Simiki application. When the application processes user-generated content or configuration parameters, it fails to properly escape or sanitize special characters that could be interpreted as HTML or JavaScript code. The specific location at line 54 of the generators.py file suggests that this is where the application constructs HTML output or handles content rendering, making it a critical point of failure in the application's security architecture. This flaw is particularly dangerous because it affects the core functionality of a static site generator, meaning that any content processed through this component could become a vector for malicious attacks. The vulnerability enables attackers to inject malicious scripts that execute in the context of legitimate users, creating a persistent threat that could be exploited across multiple sessions and user interactions.
The operational impact of CVE-2020-19000 extends beyond simple code execution, as it fundamentally compromises the security posture of any website built using vulnerable versions of Simiki. When exploited, this vulnerability allows attackers to perform a wide range of malicious activities including but not limited to stealing user session cookies, redirecting users to malicious websites, defacing content, or even establishing persistent backdoors within the compromised site. The implications are severe because static site generators are often used for documentation sites, blogs, and knowledge bases where users trust the content and may have access to sensitive information. The vulnerability can be exploited through various means including crafted content submissions, configuration file manipulation, or even through the application's API endpoints if they process user input. This attack surface is particularly concerning in environments where the static site generator is used for internal documentation or collaborative platforms where multiple users contribute content.
Organizations and developers using Simiki versions prior to 1.6.3 should immediately implement mitigations to protect their systems from potential exploitation. The primary remediation strategy involves upgrading to the patched version of Simiki that addresses this vulnerability through proper input sanitization and output encoding mechanisms. Additionally, implementing Content Security Policy headers can provide an additional layer of protection by restricting the sources from which scripts can be loaded, thereby mitigating the impact of any successful XSS attempts. The implementation of proper input validation and output encoding should be enforced throughout the application's codebase, particularly in areas where user content is processed or rendered. Security teams should also conduct comprehensive code reviews to identify similar patterns of insecure coding practices that could lead to other vulnerabilities in the application. This vulnerability serves as a reminder of the critical importance of implementing proper security controls during the development lifecycle and demonstrates how seemingly minor oversights in input handling can lead to severe security consequences. The ATT&CK framework categorizes this vulnerability under the T1059.007 technique for script injection, highlighting its potential for abuse in automated attack scenarios and emphasizing the need for robust application-level defenses.