CVE-2018-20135 in GALAXY Apps
Summary
by MITRE
Samsung Galaxy Apps before 4.4.01.7 allows modification of the hostname used for load balancing on installations of applications through a man-in-the-middle attack. An attacker may trick Galaxy Apps into using an arbitrary hostname for which the attacker can provide a valid SSL certificate, and emulate the API of the app store to modify existing apps at installation time. The specific flaw involves an HTTP method to obtain the load-balanced hostname that enforces SSL only after obtaining a hostname from the load balancer, and a missing app signature validation in the application XML. An attacker can exploit this vulnerability to achieve Remote Code Execution on the device. The Samsung ID is SVE-2018-12071.
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Analysis
by VulDB Data Team • 09/28/2023
This vulnerability exists in Samsung Galaxy Apps version prior to 4.4.01.7 and represents a critical security flaw that enables man-in-the-middle attacks through improper hostname validation and SSL certificate handling. The vulnerability stems from a specific implementation where the application first retrieves a load-balanced hostname from a server without enforcing SSL encryption during this initial phase. This design flaw allows attackers to intercept and manipulate the hostname resolution process, effectively redirecting the application to a malicious server that can present a valid SSL certificate. The vulnerability operates at the network layer where the HTTP communication flow is improperly structured, creating an opportunity for attackers to establish a false trust relationship with the victim device. The attack chain begins with the initial hostname resolution where no SSL enforcement occurs, followed by the attacker's ability to provide a legitimate SSL certificate for the manipulated hostname. This architectural weakness directly violates security principle of defense in depth, as the initial connection lacks proper authentication mechanisms.
The technical implementation of this vulnerability involves a specific HTTP communication pattern that processes hostname resolution before enforcing SSL certificate validation. When Galaxy Apps attempts to establish communication with the load balancer, it first performs a hostname lookup without SSL enforcement, allowing an attacker to intercept and redirect this process. The subsequent SSL validation occurs only after the hostname has been resolved, providing an attack window where the attacker can control the network path. Additionally, the vulnerability includes a critical missing validation of application signatures within the application XML structure, which allows attackers to modify existing applications during installation time. This dual weakness creates a perfect storm where network-level manipulation combined with application-level signature bypass enables complete control over the installation process. The missing signature validation represents a fundamental failure in the application verification mechanism, as defined by CWE-295 for improper certificate validation and CWE-347 for insufficient cryptographic validation. This vulnerability directly maps to ATT&CK technique T1190 for exploit for execution and T1059 for command and scripting interpreter, as it enables remote code execution through legitimate application installation mechanisms.
The operational impact of this vulnerability extends beyond simple data interception to full device compromise through remote code execution capabilities. Attackers can leverage this vulnerability to install malicious applications, modify existing legitimate applications, or even execute arbitrary code on the target device without user interaction. The ability to emulate the app store API means attackers can present themselves as legitimate service providers, making the attack more convincing and harder to detect. The vulnerability affects not only individual user devices but also represents a potential vector for large-scale attacks, as the Galaxy Apps platform serves millions of users globally. The attack requires minimal sophistication to execute, making it particularly dangerous as it can be exploited by threat actors with basic network manipulation capabilities. The combination of network-level interception and application-level signature bypass creates a comprehensive attack surface that can be exploited for persistent access, data exfiltration, and further lateral movement within compromised networks. Organizations and individuals using affected Samsung Galaxy Apps versions face significant risk of unauthorized application installation, potential data loss, and complete device compromise.
Mitigation strategies for this vulnerability require immediate patching of affected Galaxy Apps installations to version 4.4.01.7 or later, which implements proper SSL enforcement during hostname resolution and adds signature validation mechanisms. Network administrators should implement additional monitoring for suspicious hostname resolution patterns and SSL certificate changes that might indicate man-in-the-middle activity. The recommended approach includes deploying network segmentation to limit access to application distribution servers and implementing certificate pinning mechanisms where possible. Organizations should also consider deploying mobile device management solutions that can enforce application integrity checks and monitor for unauthorized application installations. Security teams must conduct thorough vulnerability assessments to identify any other applications or systems that might be vulnerable to similar hostname resolution and SSL enforcement flaws. The fix addresses the core architectural issue by ensuring SSL enforcement occurs immediately upon hostname resolution, preventing attackers from manipulating the initial connection phase. Additionally, the patch implements proper signature validation in application XML files, preventing modification of applications during installation time. This vulnerability demonstrates the critical importance of proper SSL implementation and signature validation, as outlined in industry standards such as NIST SP 800-52 for certificate validation and OWASP Mobile Top 10 for mobile security vulnerabilities.