vulnerability / NVI-00014111 / Revision 1
mppx: Gas Draining with access list
GitHub lists this reviewed advisory for mppx. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
mppx
source listed< 0.8.2
### Details When the server acts as the fee_payer, `mppx` 0.6.27 copies the client-supplied EIP-2930 access list verbatim into the cosigned fee-payer transaction. The TypeScript SDK's fee-payer cosigning path accepts any `access_list` the client includes in the 0x78 `FeePayerEnvelope` without inspecting its length or contents. Access list gas is charged **intrinsically** — before any opcode executes — regardless of whether the listed addresses are ever touched. An attacker submits a valid `transferWithMemo` alongside fabricated address-only access list entries. The server validates calldata and gas parameters but never inspects `access_list` length. It cosigns and broadcasts a transaction that costs the fee-payer wallet `N × 2,400` extra gas per request with no corresponding work performed on-chain. At the default of 180 entries and 100 Gwei `max_fee_per_gas`, this inflates the fee-payer cost from the normal ~51,287 gas to ~483,287 gas — a **9.4× multiplier** — while staying within the `FeePayerPolicy` cap of 500K gas, the Node.js 16 KB header limit, and the Moderato RPC's `eth_call` simulation budget (verified empirically at 180 entries). ### PoC The PoC is provided below. It
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-vc9j-9wph-qghj ↗
GitHub Advisory Database · vendor advisory
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Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.