CVE-2021-32245 in PageKit
Summary
by MITRE • 06/17/2021
In PageKit v1.0.18, a user can upload SVG files in the file upload portion of the CMS. These SVG files can contain malicious scripts. This file will be uploaded to the system and it will not be stripped or filtered. The user can create a link on the website pointing to "/storage/exp.svg" that will point to http://localhost/pagekit/storage/exp.svg. When a user comes along to click that link, it will trigger a XSS attack.
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Analysis
by VulDB Data Team • 06/21/2021
The vulnerability identified as CVE-2021-32245 represents a critical cross-site scripting flaw in PageKit version 1.0.18 that stems from inadequate input validation and sanitization of uploaded file types. This issue specifically affects the content management system's file upload functionality where SVG (Scalable Vector Graphics) files are permitted without proper security filtering or sanitization processes. The vulnerability is classified under CWE-79 as a cross-site scripting weakness, which occurs when an application incorporates untrusted data into web pages without proper validation or escaping mechanisms.
The technical exploitation of this vulnerability occurs through the manipulation of SVG file content to include malicious script payloads that can execute within the context of a victim's browser when the compromised file is accessed. The attacker can upload a specially crafted SVG file containing embedded JavaScript code that will execute when the file is served to users who click on links pointing to the uploaded file location. The attack vector specifically targets the "/storage/exp.svg" path where the malicious file is stored and accessible via the local system endpoint http://localhost/pagekit/storage/exp.svg. This approach leverages the trust relationship between the web application and its file storage system, allowing attackers to bypass normal security restrictions that would typically prevent execution of malicious code.
The operational impact of this vulnerability is significant as it allows attackers to execute arbitrary JavaScript code in the context of any user's browser who accesses the malicious SVG file. This creates a persistent threat that can be used to steal session cookies, perform unauthorized actions on behalf of users, redirect them to malicious sites, or harvest sensitive information from authenticated sessions. The vulnerability is particularly dangerous because it requires minimal user interaction beyond clicking a link, making it susceptible to social engineering attacks where users might be tricked into visiting compromised pages. The attack can be executed against any user who has access to the vulnerable PageKit installation, potentially affecting administrators, content editors, or regular website visitors.
Mitigation strategies for CVE-2021-32245 should focus on implementing comprehensive file upload validation and sanitization processes that prevent the execution of malicious code within uploaded files. Organizations should immediately upgrade to a patched version of PageKit that addresses this vulnerability through proper input filtering and content validation. Additional security measures include implementing strict file type validation that rejects SVG files with embedded scripts, using Content Security Policy headers to restrict script execution, and implementing proper file access controls that prevent direct execution of uploaded content. The ATT&CK framework categorizes this vulnerability under T1059.007 for scripting languages and T1566 for phishing techniques, highlighting the need for both technical controls and user awareness training to prevent exploitation. System administrators should also consider implementing web application firewalls and monitoring for suspicious file upload activities to detect potential exploitation attempts.