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Fencer Intel
medium 6.9

CVE-2025-54427 json

Polkadot Frontier contains missing `check_inherent` for `note_min_gas_price_target` inflates gas price

published last yr. modified 4mo ago also EUVD-2025-22951

cvss
6.9
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

Polkadot Frontier is an Ethereum and EVM compatibility layer for Polkadot and Substrate. The extrinsic note_min_gas_price_target is an inherent extrinsic, meaning only the block producer can call it. To ensure correctness, the ProvideInherent trait should be implemented for each inherent, which includes the check_inherent call. This allows other nodes to verify if the input (in this case, the target value) is correct. However, prior to commit a754b3d, the check_inherent function has not been implemented for note_min_gas_price_target. This lets the block producer set the target value without verification. The target is then used to set the MinGasPrice, which has an upper and lower bound defined in the on_initialize hook. The block producer can set the target to the upper bound. Which also increases the upper and lower bounds for the next block. Over time, this could result in continuously raising the gas price, making contract execution too expensive and ineffective for users. An attacker could use this flaw to manipulate the gas price, potentially leading to significantly inflated transaction fees. Such manipulation could render contract execution prohibitively expensive for users, effectively resulting in a denial-of-service condition for the network. This is fixed in version a754b3d.

Patch / fix

Is CVE-2025-54427 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • polkadot-evm frontier

Classification

Weakness
  • CWE-682 Incorrect Calculation
  • CWE-754 Improper Check for Unusual or Exceptional Conditions

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.