CVE-2018-15832 in Uplay Desktop Client
Summary
by MITRE
upc.exe in Ubisoft Uplay Desktop Client versions 63.0.5699.0 allows remote attackers to execute arbitrary code. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the processing of URI handlers. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code under the context of the current process.
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Analysis
by VulDB Data Team • 03/25/2020
The vulnerability identified as CVE-2018-15832 affects the Ubisoft Uplay Desktop Client version 63.0.5699.0 and represents a critical remote code execution flaw that can be exploited through malicious web pages or files. This vulnerability specifically targets the upc.exe component within the Uplay client suite, which serves as the primary executable responsible for handling various client operations including URI scheme processing. The flaw exists in the client's handling of Universal Resource Identifier (URI) schemes, which are commonly used to launch applications or execute specific functions when users click on links or interact with certain file types. The vulnerability stems from insufficient input validation mechanisms that fail to properly sanitize user-supplied strings before these values are processed and executed within the system call context. This type of vulnerability falls under the CWE-78 weakness category, which specifically addresses improper neutralization of special elements used in OS commands, making it particularly dangerous as it allows attackers to inject and execute arbitrary system commands. The attack vector requires user interaction, meaning that victims must actively visit malicious web pages or open compromised files to trigger the exploit, which aligns with the ATT&CK technique T1203 for Exploitation for Client Execution. When an attacker successfully exploits this vulnerability, they can execute code with the privileges and context of the currently running Uplay process, potentially allowing for full system compromise if the process runs with elevated privileges. The security implications extend beyond simple code execution as this vulnerability could enable attackers to install malware, modify system files, or establish persistent backdoors within the victim's environment.
The technical exploitation of this vulnerability demonstrates a classic command injection flaw where user-supplied URI parameters are directly incorporated into system calls without adequate sanitization or validation. The upc.exe process likely handles various URI schemes such as uplay:// or similar protocols that are registered with the operating system to launch specific Uplay functions or navigate to particular sections within the client. When a malicious URI is processed, the application fails to validate the input string properly, allowing attackers to inject additional commands or parameters that get executed by the system shell. This vulnerability is particularly concerning because it operates at the application level within the desktop client, which often has elevated privileges and access to system resources. The lack of proper input validation creates an environment where attackers can manipulate the URI processing logic to execute arbitrary commands, potentially leading to privilege escalation or complete system compromise. The vulnerability's classification as a remote code execution issue indicates that attackers can exploit this weakness from remote locations without requiring physical access to the target system, making it a significant threat vector in enterprise environments where Uplay clients are commonly deployed. From a defensive perspective, this vulnerability highlights the importance of proper input validation and the principle of least privilege when designing desktop applications that handle external input through URI schemes or similar mechanisms.
Organizations and security professionals should implement immediate mitigations to address this vulnerability, including updating the Uplay client to versions that have patched this flaw, which typically involves applying the latest Ubisoft client updates or patches. The vulnerability's requirement for user interaction means that traditional network-based protections may not be sufficient, and organizations should consider implementing user education programs to help prevent accidental exploitation through social engineering attacks. Security teams should also monitor for suspicious URI patterns or unexpected system calls that might indicate exploitation attempts, particularly focusing on unusual command execution patterns within the Uplay process context. The implementation of application whitelisting policies that restrict execution of unauthorized binaries or scripts can provide additional protection layers. Additionally, network segmentation and web filtering solutions should be configured to block access to known malicious domains or URLs that might be used in exploitation attempts. The vulnerability's presence in a widely-used gaming platform client demonstrates the broader security implications for desktop applications and underscores the need for robust input validation across all software components that process external data. Organizations should also consider conducting security assessments of their desktop applications to identify similar URI processing vulnerabilities that might exist in other software products within their environment, as this type of flaw is commonly found in applications that handle user-supplied input through various protocol handlers or external interfaces. The remediation process should include not only patching the specific vulnerability but also implementing comprehensive security controls that address the underlying architectural weaknesses that allowed this vulnerability to exist in the first place.