CVE-2021-46888 : Security Advisory and Response

An issue was discovered in hledger before 1.23. A Stored Cross-Site Scripting (XSS) vulnerability exists in toBloodhoundJson that allows an attacker to execute JavaScript by encoding user-controlled values in a payload with base64 and parsing them with the atob function.

Understanding CVE-2021-46888

What is CVE-2021-46888?

CVE-2021-46888 is a Stored Cross-Site Scripting (XSS) vulnerability found in hledger before version 1.23. The vulnerability allows attackers to execute JavaScript by manipulating user-controlled values in a payload.

The Impact of CVE-2021-46888

This vulnerability could be exploited by malicious actors to execute arbitrary JavaScript code on the victim's browser, leading to various consequences such as unauthorized access, data theft, or further attacks.

Technical Details of CVE-2021-46888

Vulnerability Description

The vulnerability exists in the toBloodhoundJson function in hledger, where user-controlled values are encoded in base64 and parsed using the atob function, allowing for XSS attacks.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Affected Versions: All versions before 1.23

Exploitation Mechanism

The vulnerability is exploited by encoding malicious JavaScript code in base64 within user-controlled values, which are later decoded and executed using the atob function, enabling the attacker to perform XSS attacks.

Mitigation and Prevention

Immediate Steps to Take

Upgrade hledger to version 1.23 or newer to mitigate the vulnerability.
Avoid inputting untrusted data that could be executed as code in the system.
Regularly monitor for any suspicious activities on the system that could indicate an ongoing attack.

Long-Term Security Practices

Implement input validation and sanitization mechanisms to prevent XSS vulnerabilities.
Conduct security audits and code reviews to identify and address potential vulnerabilities in the application code.

Patching and Updates

Stay informed about security updates and patches released by hledger.
Apply patches promptly to ensure that the system is protected against known vulnerabilities.