CVE-2019-13645 : What You Need to Know

Firefly III versions earlier than 4.7.17.3 have a security flaw that allows for stored cross-site scripting (XSS) attacks. This vulnerability arises from a failure to properly filter user-provided data in the names of image files. The issue occurs when editing attachments at the path /attachments/edit/$file_id$, where the JavaScript code is executed. It is important to note that for an attacker to exploit this vulnerability, they need to have the same access privileges as the user.

Understanding CVE-2019-13645

Firefly III before version 4.7.17.3 is susceptible to stored XSS attacks due to inadequate filtration of user-supplied data in image file names.

What is CVE-2019-13645?

Firefly III versions prior to 4.7.17.3 are vulnerable to stored cross-site scripting (XSS) attacks.
The security flaw stems from insufficient filtering of user-provided data in image file names.
Exploitation occurs during attachment editing at a specific path, allowing execution of JavaScript code.
Attackers must possess the same access rights as the user to leverage this vulnerability.

The Impact of CVE-2019-13645

Malicious actors can execute stored XSS attacks on Firefly III instances running versions earlier than 4.7.17.3.
Successful exploitation could lead to unauthorized access, data theft, and potential compromise of user accounts.

Technical Details of CVE-2019-13645

Firefly III's vulnerability to stored XSS attacks due to inadequate filtration of user-supplied data.

Vulnerability Description

Lack of proper filtering of user-provided data in image file names.
Execution of JavaScript code during attachment editing at a specific path.

Affected Systems and Versions

Firefly III versions before 4.7.17.3.

Exploitation Mechanism

Attackers can exploit the vulnerability by editing attachments at the path /attachments/edit/$file_id$.
Requires attackers to have the same access privileges as the user.

Mitigation and Prevention

Immediate Steps to Take:

Upgrade Firefly III to version 4.7.17.3 or later to mitigate the vulnerability.
Regularly monitor for security updates and patches from the Firefly III project.

Long-Term Security Practices:

Implement secure coding practices to sanitize user input and prevent XSS vulnerabilities.
Conduct regular security assessments and penetration testing to identify and address potential security weaknesses.
Educate users on safe attachment handling practices to minimize the risk of exploitation.
Stay informed about security best practices and industry trends to enhance overall security posture.

Patching and Updates:

Apply patches and updates promptly to ensure the latest security fixes are in place.