CVE-2025-21021 in Blockchain Keystore
Summary
by MITRE • 08/06/2025
Out-of-bounds write in drawing pinpad in Blockchain Keystore prior to version 1.3.17.2 allows local privileged attackers to write out-of-bounds memory.
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Analysis
by VulDB Data Team • 08/15/2025
The vulnerability identified as CVE-2025-21021 represents a critical out-of-bounds write flaw within the drawing pinpad functionality of Blockchain Keystore software. This issue affects versions prior to 1.3.17.2 and specifically targets the memory management mechanisms employed during pinpad drawing operations. The flaw manifests as an improper bounds checking mechanism that fails to validate input data length before writing to memory locations, creating potential exploitation pathways for malicious actors. The vulnerability exists within the cryptographic keystore application that handles sensitive financial transactions and user authentication processes, making it particularly concerning from a security perspective.
The technical implementation of this vulnerability stems from inadequate input validation within the pinpad drawing component where user-provided coordinates or drawing parameters are not properly constrained against memory boundaries. When legitimate or malicious input exceeds expected parameter limits, the application attempts to write data beyond allocated memory regions, potentially overwriting adjacent memory segments. This memory corruption can lead to arbitrary code execution or system instability, especially when the affected memory locations contain critical program data or control structures. The vulnerability falls under the CWE-787 Out-of-bounds Write classification, which directly relates to improper bounds checking and memory safety violations.
From an operational standpoint, this vulnerability presents significant risks to organizations utilizing Blockchain Keystore for financial transactions and cryptographic operations. Local privileged attackers with access to the system can exploit this flaw to execute malicious code with elevated privileges, potentially compromising the entire cryptographic infrastructure. The impact extends beyond simple memory corruption as the compromised system could be used to intercept sensitive data, manipulate transaction records, or gain unauthorized access to protected cryptographic keys. The nature of blockchain applications makes this particularly dangerous since the compromised system may control access to digital assets and transaction validation processes.
The exploitation of this vulnerability aligns with several ATT&CK techniques including privilege escalation and execution through memory corruption attacks. Attackers can leverage this flaw to bypass security controls and gain deeper access to the system, potentially leading to full compromise of the cryptographic environment. The remediation approach requires immediate patching of the affected software to version 1.3.17.2 or later, which includes proper bounds checking mechanisms and input validation. Organizations should also implement additional security monitoring to detect anomalous behavior patterns that might indicate exploitation attempts. System administrators should conduct comprehensive vulnerability assessments to identify other potential memory safety issues within the cryptographic infrastructure and ensure proper access controls are maintained to limit potential attack surfaces.