CVE-2019-11341 in Smart Phone
Summary
by MITRE
On certain Samsung P(9.0) phones, an attacker with physical access can start a TCP Dump capture without the user's knowledge. This feature of the Service Mode application is available after entering the *#9900# check code, but is protected by an OTP password. However, this password is created locally and (due to mishandling of cryptography) can be obtained easily by reversing the password creation logic.
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Analysis
by VulDB Data Team • 01/07/2024
The vulnerability identified as CVE-2019-11341 represents a critical security flaw in Samsung Galaxy S9 and other devices running Android 9.0 operating system. This issue stems from improper implementation of cryptographic mechanisms within the Service Mode application, which provides advanced diagnostic and testing features to authorized personnel. The vulnerability specifically affects devices where the service mode can be accessed through the secret code *#9900# and subsequently exploited through a weakly implemented one-time password protection mechanism. The flaw allows an attacker with physical access to a device to bypass the authentication barrier and initiate network traffic capture capabilities without user awareness or consent. This represents a significant compromise of device security and user privacy, as it enables passive network monitoring and data interception.
The technical implementation of this vulnerability involves a cryptographic weakness in the password generation algorithm used to protect the Service Mode application. The OTP password is generated locally on the device but suffers from poor entropy and predictable generation patterns that make it susceptible to reverse engineering. Security researchers discovered that the password creation logic could be analyzed through reverse engineering techniques, allowing attackers to deduce the password generation algorithm and subsequently obtain valid credentials without prior knowledge. This flaw aligns with CWE-330 weakness category, which specifically addresses the use of weak or predictable random number generators in cryptographic contexts. The vulnerability demonstrates a fundamental misunderstanding of cryptographic best practices and proper password derivation mechanisms.
The operational impact of this vulnerability extends beyond simple privacy concerns to encompass potential data breaches and network surveillance capabilities. When an attacker successfully bypasses the password protection, they gain access to the TCP Dump functionality which can capture and log all network traffic passing through the device. This capability enables comprehensive network monitoring, packet inspection, and potential data extraction from communications. The vulnerability is particularly dangerous because it operates silently in the background without user notification, making it impossible for device owners to detect unauthorized access or monitoring activities. The attack requires only physical access to the device and basic reverse engineering skills, making it accessible to a wide range of threat actors. This weakness violates fundamental security principles of user consent and transparency in device operations.
Mitigation strategies for this vulnerability should focus on both immediate remediation and long-term security improvements. Samsung addressed this issue through firmware updates that strengthened the password generation algorithm and improved the cryptographic implementation within Service Mode. Device users should ensure their devices are updated to the latest security patches, particularly those released after the vulnerability disclosure. Organizations should implement device management policies that regularly check for and apply security updates. The vulnerability highlights the importance of proper cryptographic implementation and the need for thorough security testing of privileged applications. Security professionals should consider this weakness when conducting device security assessments and recommend additional layers of protection such as device encryption, secure boot mechanisms, and regular security audits to prevent similar vulnerabilities from manifesting in other applications or systems. The incident serves as a reminder of the critical importance of cryptographic hygiene and proper implementation of security controls in mobile device operating systems.