CVE-2023-21508 in Blockchain Keystore
Summary
by MITRE • 05/05/2023
Out-of-bounds Write vulnerability while processing BC_TUI_CMD_SEND_RESOURCE_DATA command in bc_tui trustlet from Samsung Blockchain Keystore prior to version 1.3.12.1 allows local attacker to execute arbitrary code.
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Analysis
by VulDB Data Team • 09/18/2025
The vulnerability identified as CVE-2023-21508 represents a critical out-of-bounds write flaw within the bc_tui trustlet component of Samsung Blockchain Keystore software. This issue affects versions prior to 1.3.12.1 and specifically manifests during the processing of BC_TUI_CMD_SEND_RESOURCE_DATA commands. The trustlet environment operates within a secure execution context designed to handle blockchain-related cryptographic operations, making this vulnerability particularly concerning for mobile security architectures. The flaw stems from inadequate input validation and bounds checking mechanisms within the command processing logic, creating a pathway for malicious code execution through crafted resource data payloads.
The technical exploitation of this vulnerability occurs when a local attacker crafts malicious input data that triggers an out-of-bounds write operation in memory allocated for processing blockchain resource commands. This type of vulnerability falls under CWE-787, which specifically addresses out-of-bounds writes, and represents a classic buffer overflow scenario where attacker-controlled data is written beyond the allocated memory boundaries. The bc_tui trustlet operates with elevated privileges within the Samsung blockchain keystore framework, meaning that successful exploitation could enable an attacker to execute arbitrary code with the same privileges as the trustlet itself. The vulnerability's local nature means that the attacker must already have access to the device, typically through user interaction or pre-existing compromise, but the privilege escalation potential makes it particularly dangerous.
From an operational perspective, this vulnerability presents significant risk to Samsung mobile device users who utilize blockchain applications or services integrated with the Samsung Blockchain Keystore. The attack surface is limited to devices running vulnerable versions of the software, but given Samsung's market presence and the widespread use of blockchain-based applications on Android devices, the potential impact is substantial. The vulnerability could be exploited to gain persistent access to device resources, potentially compromising sensitive blockchain keys, transaction data, or other cryptographic material stored within the secure keystore environment. Security researchers have noted that trustlet-based vulnerabilities often provide attackers with pathways to bypass traditional security controls, as these components operate outside standard operating system security boundaries.
Mitigation strategies for CVE-2023-21508 primarily involve updating to Samsung Blockchain Keystore version 1.3.12.1 or later, which contains the necessary patches to address the out-of-bounds write condition. Organizations should implement comprehensive patch management protocols to ensure all affected devices receive updates promptly. Additionally, security monitoring should focus on detecting anomalous behavior patterns in blockchain keystore operations, particularly around resource data processing commands. Network administrators should consider implementing device access controls and privilege separation measures to limit the potential impact of successful exploitation. The vulnerability demonstrates the importance of robust input validation in secure execution environments and aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation may involve crafting malicious commands to trigger the vulnerable code path. System hardening measures should include memory protection mechanisms such as stack canaries and address space layout randomization to make exploitation more difficult. The incident highlights the critical need for continuous security assessment of trusted execution environments and secure elements within mobile platforms, as these components often serve as primary targets for sophisticated attackers seeking to compromise device-level security.