CVE-2017-12116 in JSON-RPC
Summary
by MITRE
An exploitable improper authorization vulnerability exists in miner_setGasPrice API of cpp-ethereum's JSON-RPC (commit 4e1015743b95821849d001618a7ce82c7c073768). A JSON request can cause an access to the restricted functionality resulting in authorization bypass. An attacker can send JSON to trigger this vulnerability.
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Analysis
by VulDB Data Team • 02/02/2023
The CVE-2017-12116 vulnerability represents a critical authorization bypass flaw within the cpp-ethereum client's JSON-RPC interface, specifically affecting the miner_setGasPrice 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 unauthorized users can exploit the JSON-RPC interface to manipulate gas pricing parameters, effectively bypassing the intended authorization controls that should restrict such modifications to privileged entities only.
The technical implementation of this vulnerability resides in the improper handling of authentication tokens and permission checks within the JSON-RPC request processing pipeline. When a malicious actor submits a crafted JSON-RPC request to the miner_setGasPrice endpoint, the system fails to verify whether the requesting entity possesses the necessary administrative privileges to modify mining parameters. This flaw operates at the application layer and directly violates the principle of least privilege, allowing unauthorized access to functionality that should remain restricted to authorized mining operators or system administrators. The vulnerability is particularly concerning because it enables attackers to manipulate transaction fees and mining rewards, potentially disrupting the network's economic incentives and consensus mechanisms.
The operational impact of CVE-2017-12116 extends beyond simple unauthorized access, creating potential for significant network disruption and financial loss within the ethereum ecosystem. Attackers could exploit this vulnerability to alter gas pricing settings, potentially leading to transaction spamming or denial of service conditions that affect network performance. The vulnerability also poses risks to mining pool operations where unauthorized modifications to gas pricing could result in financial losses for legitimate miners. From a cybersecurity perspective, this flaw represents a direct violation of the CIA triad, specifically undermining the system's integrity and availability properties. Network operators and users may experience compromised trust in the mining infrastructure, as the vulnerability exposes the system to unauthorized modifications that could destabilize the entire blockchain network.
Mitigation strategies for CVE-2017-12116 should prioritize immediate patching of affected cpp-ethereum versions, with comprehensive network monitoring to detect potential exploitation attempts. Organizations should implement strict access controls and authentication mechanisms for JSON-RPC interfaces, including the enforcement of API keys and proper user permission validation. The vulnerability aligns with CWE-284, which specifically addresses improper access control, and represents a clear violation of ATT&CK technique T1078 for valid accounts and T1068 for exploit for privilege escalation. Network segmentation and rate limiting for JSON-RPC endpoints can provide additional defensive layers, while regular security audits should verify that all API endpoints properly implement authorization checks. System administrators should also consider implementing intrusion detection systems to monitor for suspicious JSON-RPC activity patterns that may indicate exploitation attempts.