CVE-2020-15111 Explained : Impact and Mitigation

In Fiber before version 1.12.6, a CRLF vulnerability exists due to unescaped filenames in c.Attachment(), allowing for potential attacks. Learn about the impact, technical details, and mitigation steps.

Understanding CVE-2020-15111

This CVE involves a CRLF vulnerability in Fiber before version 1.12.6, posing risks of CRLF injection attacks.

What is CVE-2020-15111?

The vulnerability arises from unescaped filenames in c.Attachment(), enabling malicious activities like file name manipulation and unauthorized redirection.

The Impact of CVE-2020-15111

CVSS Score: 4.2 (Medium)
Attack Vector: Network
Attack Complexity: High
User Interaction: Required
Confidentiality Impact: Low
Integrity Impact: Low
Privileges Required: None
Scope: Unchanged
Availability Impact: None

Technical Details of CVE-2020-15111

This section covers the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The issue stems from unescaped filenames in c.Attachment(), making it susceptible to CRLF injection attacks.

Affected Systems and Versions

Affected Product: Fiber
Vendor: gofiber
Vulnerable Versions: < 1.12.6

Exploitation Mechanism

Attackers can upload custom filenames to manipulate downloaded files, redirect users, or alter authorization headers.

Mitigation and Prevention

Protect your systems from CVE-2020-15111 by following these mitigation strategies.

Immediate Steps to Take

Serialize input before passing it to ctx.Attachment() to prevent CRLF injection.

Long-Term Security Practices

Regularly update Fiber to the latest version to patch known vulnerabilities.
Educate users on safe file handling practices to minimize risks.
Monitor and restrict file upload capabilities to prevent malicious activities.
Implement security headers to mitigate potential attacks.
Conduct security audits to identify and address vulnerabilities.

Patching and Updates

Stay informed about security advisories and apply patches promptly to secure your systems.