CVE-2025-54427 is a medium-severity vulnerability affecting the Polkadot Frontier project, an Ethereum Virtual Machine (EVM) compatibility layer for the Polkadot and Substrate blockchain ecosystems. The vulnerability arises from an incorrect implementation of the ProvideInherent trait for the inherent extrinsic note_min_gas_price_target, which is exclusively callable by the block producer. This extrinsic sets a target value for the minimum gas price (MinGasPrice) used in transaction fee calculations. Prior to the fix introduced in commit a754b3d, the check_inherent function was not implemented for this extrinsic, meaning that the block producer could set the target gas price value without any verification by other nodes. The MinGasPrice is bounded by upper and lower limits that are dynamically adjusted in the on_initialize hook of each block. Because the block producer can set the target to the upper bound unchecked, this allows them to incrementally raise both the upper and lower bounds for subsequent blocks. Over time, this manipulation can cause the gas price to inflate continuously, making contract execution prohibitively expensive for users. This effectively results in a denial-of-service (DoS) condition for the network by pricing out legitimate transactions. The vulnerability does not require authentication beyond block producer privileges, which are inherent to the consensus mechanism, and no user interaction is needed. Although no known exploits are reported in the wild, the flaw could be exploited by a malicious or compromised block producer to degrade network usability and trust. The vulnerability is tracked under CWE-682 (Incorrect Calculation) and CWE-754 (Improper Check for Unusual or Exceptional Conditions), and has a CVSS 4.0 base score of 6.9, reflecting a medium severity level. The issue was resolved by implementing the check_inherent function to verify the target value, preventing unchecked manipulation of gas price bounds.

For European organizations utilizing Polkadot or Substrate-based blockchains with the Frontier EVM compatibility layer, this vulnerability poses a significant risk to operational continuity and cost efficiency. Inflated gas prices can lead to drastically increased transaction fees, deterring users and developers from executing smart contracts or transacting on the network. This can disrupt decentralized applications (dApps), financial services, and supply chain solutions relying on these blockchains, potentially causing financial losses and reputational damage. Additionally, the effective denial-of-service condition could undermine trust in blockchain-based services, impacting adoption and regulatory compliance efforts within Europe. Organizations running validator nodes or block producers are particularly at risk, as a compromised or malicious block producer could exploit this flaw to degrade network performance. Furthermore, the economic impact of inflated fees could disproportionately affect smaller enterprises and startups relying on cost-effective blockchain transactions. Given the growing interest and investment in blockchain technologies across Europe, this vulnerability could hinder innovation and deployment of decentralized solutions if not addressed promptly.

European organizations should ensure that all Polkadot Frontier deployments are updated to include the fix introduced in commit a754b3d or later versions that implement the check_inherent function for the note_min_gas_price_target extrinsic. Validators and block producers must audit their node software to confirm the presence of this patch. Network operators should monitor gas price metrics for abnormal inflation patterns that could indicate exploitation attempts. Implementing additional monitoring and alerting on gas price bounds and transaction fee anomalies can provide early detection of manipulation. Organizations should also consider restricting block producer roles to trusted entities and employ multi-signature or decentralized consensus mechanisms for critical parameter changes to reduce the risk of single-actor manipulation. Participation in community governance and security forums related to Polkadot and Frontier can help stay informed about emerging threats and patches. Finally, conducting regular security assessments and code reviews of blockchain node software is recommended to identify and remediate similar logic flaws proactively.