CVE-2017-12115 in JSON-RPC
Summary
by MITRE
An exploitable improper authorization vulnerability exists in miner_setEtherbase API of cpp-ethereum's JSON-RPC (commit 4e1015743b95821849d001618a7ce82c7c073768). A JSON request can cause an access to the restricted functionality resulting in authorization bypass.
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Analysis
by VulDB Data Team • 02/02/2023
The vulnerability described in CVE-2017-12115 represents a critical improper authorization flaw within the cpp-ethereum client's JSON-RPC interface, specifically affecting the miner_setEtherbase API endpoint. This vulnerability stems from inadequate access control mechanisms that fail to properly validate user permissions before executing sensitive operations. The issue manifests when a malicious actor submits a crafted JSON-RPC request that bypasses the intended authorization checks, allowing unauthorized access to mining configuration functions that should be restricted to privileged users only. The vulnerability exists in the commit hash 4e1015743b95821849d001618a7ce82c7c073768, indicating a specific codebase version where the authorization logic was insufficiently implemented or incorrectly configured.
The technical exploitation of this vulnerability occurs through manipulation of the JSON-RPC protocol interface, where the miner_setEtherbase function allows users to set the Ethereum address that will receive mining rewards. When proper authorization checks are bypassed, any remote attacker can potentially modify this configuration without proper authentication, effectively enabling them to redirect mining rewards to addresses they control. This represents a direct violation of the principle of least privilege and demonstrates a failure in the access control implementation. The vulnerability is classified under CWE-285, which specifically addresses improper authorization issues in software systems, and aligns with ATT&CK technique T1078 for Valid Accounts and T1566 for Phishing, as it allows for unauthorized access to mining operations that could be leveraged for financial gain or network disruption.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to manipulate the mining infrastructure of affected systems. In a blockchain mining context, this could result in significant financial loss for legitimate miners who lose control over their reward distribution. The vulnerability also poses risks to network integrity, as unauthorized modifications to mining configurations could potentially disrupt consensus mechanisms or create opportunities for 51% attacks. Organizations running cpp-ethereum nodes without proper network segmentation or additional authentication layers face severe risks, as this vulnerability can be exploited remotely without requiring physical access or additional credentials. The implications are particularly severe in enterprise environments where mining operations are part of larger financial infrastructure, as it could lead to unauthorized cryptocurrency generation and potential regulatory compliance violations.
Mitigation strategies for CVE-2017-12115 should focus on implementing robust authentication and authorization controls within the JSON-RPC interface. System administrators must ensure that all API endpoints properly validate user credentials and enforce access control policies before executing sensitive operations. The recommended approach includes implementing mandatory authentication for all mining-related API functions, establishing role-based access controls, and deploying network segmentation to limit exposure of the JSON-RPC interface to trusted networks only. Additionally, organizations should consider implementing API rate limiting and monitoring mechanisms to detect anomalous access patterns that might indicate exploitation attempts. The fix requires updating the cpp-ethereum client to a version that properly implements authorization checks for the miner_setEtherbase function, and organizations should conduct comprehensive security audits of their blockchain infrastructure to identify similar authorization flaws in other API endpoints. Regular security updates and vulnerability assessments should be implemented as part of the operational security posture to prevent similar issues from arising in the future, with particular attention to the ATT&CK framework's recommendations for credential access and privilege escalation techniques that could exploit such authorization bypass vulnerabilities.