CVE-2016-7991 in Galaxy
Summary
by MITRE
On Samsung Galaxy S4 through S7 devices, the "omacp" app ignores security information embedded in the OMACP messages resulting in remote unsolicited WAP Push SMS messages being accepted, parsed, and handled by the device, leading to unauthorized configuration changes, a subset of SVE-2016-6542.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 05/21/2019
The vulnerability identified as CVE-2016-7991 affects Samsung Galaxy S4 through S7 mobile devices and represents a critical flaw in the handling of OMACP (Open Mobile Alliance Client Provisioning) messages. This security issue stems from the "omacp" application's failure to properly validate security information contained within OMACP messages, creating an avenue for malicious actors to exploit the device's provisioning mechanism. The flaw specifically impacts the device's WAP Push SMS handling capabilities, where the system accepts, parses, and processes unsolicited messages without adequate verification of their authenticity or source. This vulnerability falls under the broader category of configuration management flaws and represents a subset of the more comprehensive SVE-2016-6542 vulnerability family that affects Samsung's mobile device provisioning systems. The issue is particularly concerning because it allows for unauthorized configuration changes to be applied to the device through seemingly legitimate WAP Push communications, which are typically used for legitimate provisioning purposes such as updating network settings or application configurations.
The technical implementation of this vulnerability involves the omacp application's insufficient validation of OMACP message integrity and authenticity. When a device receives a WAP Push SMS message containing OMACP data, the application should verify the embedded security information to ensure the message originates from a trusted source and has not been tampered with during transmission. However, the Samsung implementation fails to perform this crucial validation step, allowing any OMACP message to be processed regardless of its security credentials. This flaw enables attackers to craft malicious OMACP messages that appear legitimate to the device's provisioning system, bypassing normal security controls that would typically prevent unauthorized configuration modifications. The vulnerability is classified as a weakness in the OMA Client Provisioning framework implementation, specifically related to inadequate input validation and security parameter handling, which aligns with CWE-20 (Improper Input Validation) and CWE-347 (Improper Verification of Cryptographic Signature) categories. The attack vector requires only the ability to send WAP Push SMS messages to the target device, making it particularly dangerous as it can be exploited remotely without requiring physical access or complex preconditions.
The operational impact of CVE-2016-7991 extends far beyond simple unauthorized configuration changes, potentially enabling attackers to gain significant control over affected Samsung devices. Through manipulation of OMACP messages, malicious actors could alter network settings, modify application configurations, redirect traffic, or even install unauthorized applications on the device. This capability represents a substantial risk to user privacy and device security, as it allows attackers to modify device behavior without user knowledge or consent. The vulnerability's impact is particularly severe because it operates at a system level within the device's provisioning framework, potentially allowing attackers to establish persistent access or create backdoors for future exploitation. The flaw also demonstrates a broader pattern of insufficient security controls in mobile device provisioning systems, which are critical for maintaining device integrity and preventing unauthorized modifications. From an attacker's perspective, this vulnerability provides a path to compromise device security through a relatively simple attack method involving SMS message manipulation, making it an attractive target for threat actors seeking to exploit mobile device security weaknesses.
Mitigation strategies for CVE-2016-7991 require both immediate device-level actions and broader security architecture improvements. Samsung released security patches and firmware updates to address this vulnerability, which users should install immediately to protect their devices. Organizations deploying Samsung devices should implement network-level controls to monitor and filter WAP Push SMS traffic, particularly for messages containing OMACP content. The security community recommends disabling unnecessary WAP Push functionality when possible and implementing strict access controls for provisioning services. From a defensive perspective, this vulnerability highlights the importance of proper input validation and security parameter verification in mobile device frameworks, aligning with ATT&CK technique T1059.007 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) methodologies that emphasize the need for robust validation of system inputs. Network administrators should consider implementing SMS filtering solutions and monitoring for unusual provisioning message patterns, while device security teams should ensure that all provisioning frameworks properly validate cryptographic signatures and security credentials before processing any configuration updates. The vulnerability also underscores the necessity of regular security assessments of mobile device provisioning systems and the importance of adhering to secure coding practices that prevent similar issues in future implementations.