CVE-2019-13020 in Carousel
Summary
by MITRE
The fetch API in Tightrope Media Carousel before 7.1.3 has CarouselAPI/v0/fetch?url= SSRF. This has two potential areas for abuse. First, a specially crafted URL could be used in a phishing attack to hijack the trust the user and the browser have with the website and could serve malicious content from a third-party attacker-controlled system. Second, arguably more severe, is the potential for an attacker to circumvent firewall controls, by proxying traffic, unauthenticated, into the internal network from the internet.
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Analysis
by VulDB Data Team • 08/06/2020
The vulnerability identified as CVE-2019-13020 affects the fetch API implementation within Tightrope Media Carousel versions prior to 7.1.3, specifically targeting the CarouselAPI/v0/fetch?url= endpoint which is susceptible to Server-Side Request Forgery attacks. This flaw represents a critical security weakness that allows remote attackers to manipulate the application's request handling mechanism, potentially compromising the entire network infrastructure. The vulnerability falls under the Common Weakness Enumeration category CWE-918, which specifically addresses Server-Side Request Forgery, and aligns with ATT&CK technique T1071.004 for Application Layer Protocol: DNS, as it enables attackers to leverage the application's legitimate network capabilities for malicious purposes. The core issue stems from insufficient input validation and sanitization of the URL parameter, allowing attackers to specify arbitrary endpoints that the application will attempt to fetch on behalf of the user. This creates a dangerous trust relationship where the application becomes an unwitting proxy for attacker-controlled requests.
The operational impact of this vulnerability extends beyond simple data exfiltration, as it provides attackers with a sophisticated method for bypassing traditional network security controls. When an attacker crafts a malicious URL parameter, the application will attempt to fetch content from that location using its own credentials and network access privileges, effectively enabling the attacker to probe internal systems that would normally be protected by firewalls and network segmentation. This proxy functionality allows for internal network reconnaissance, service enumeration, and potential exploitation of vulnerable internal systems that are not directly exposed to the internet. The dual nature of this vulnerability means that attackers can simultaneously conduct phishing operations by serving malicious content through the trusted domain while also using the same mechanism to perform internal network reconnaissance and attack surface mapping. The attack vector is particularly dangerous because it leverages the legitimate trust relationship between the application and its network infrastructure, making detection more challenging.
The security implications of this SSRF vulnerability are severe and multifaceted, as it essentially transforms the vulnerable application into a network reconnaissance and attack tool. Attackers can use this vulnerability to scan internal network ranges, identify running services, and potentially exploit vulnerabilities in internal systems that are normally protected by firewalls. The phishing component adds another layer of complexity, as attackers can craft URLs that appear legitimate to users while simultaneously serving malicious content from attacker-controlled servers. This creates a sophisticated attack scenario where users trust the application's domain while unknowingly accessing malicious content. The vulnerability also demonstrates the importance of implementing proper input validation and the principle of least privilege in web applications. Organizations should consider implementing network segmentation, implementing proper URL validation, and utilizing web application firewalls to prevent such attacks. The vulnerability aligns with ATT&CK technique T1566.001 for Phishing: Spearphishing Attachment, as it enables the delivery of malicious content through trusted application endpoints. Additionally, the vulnerability highlights the need for comprehensive security testing including security code reviews, penetration testing, and proper network architecture design that prevents applications from acting as unauthorized network proxies.