Ammplify maker spot-price manipulation — AuditVault 63167

Source & credit. Reproduction of a public audit finding curated by AuditVault — the original finding: 63167. Standalone Foundry PoC and full write-up: 63167-ammplify-maker-spot-price_exp in the evm-hack-registry mirror.

Vulnerability classes: vuln/oracle/spot-price · vuln/defi/fee-manipulation

Reproduction: Fully local synthetic reduction. Run forge test -vvv in this folder; no live RPC is required.

Key info#

Field	Value
Protocol	Audit finding 63167
Impact	High
Loss	Reduced invariant reproduced; no live funds moved
Attacker EOA	Configured synthetic caller
Attack contract	`Exploit`
Attack tx	Local Foundry `Exploit.attack()` call
Chain · block · date	Ethereum model · block 1 · synthetic
Bug class	See vulnerability-class tags above
Vulnerable contract	`Vulnerable` in `test/63167-ammplify-maker-spot-price.sol`
Attack contract	`Exploit`
Compiler	Solidity 0.8.24
Reproduction	Local reduced model

TL;DR#

Maker deposits value liquidity using a manipulable Uniswap spot price.

Background#

The report identifies a state/accounting boundary that can be reached by an untrusted caller. This self-contained model keeps the relevant variables and call ordering while removing unrelated protocol dependencies.

The vulnerable code#

The minimized victim and attack contracts are in test/63167-ammplify-maker-spot-price.sol. The marked operation is executed by Exploit.attack() and asserted by the Foundry test.

Root cause#

The vulnerable operation omits the validation or state update required by the report, so the resulting state no longer matches the intended invariant.

Preconditions#

The affected entry point is deployed and reachable; no privileged role is needed in this reduced reproduction.

Attack walkthrough#

Deploy the reduced victim from Exploit.
Execute the reported call sequence.
Assert the resulting state mismatch in test_exploit.

Diagrams#

flowchart TD A[Attacker] --> B[Vulnerable entry point] B --> C[Missing check or state update] C --> D[Incorrect state / denial of service]

Remediation#

Validate caller-controlled inputs and perform the accounting/state transition atomically before any external effect. Add a regression test for the reported invariant.

How to reproduce#

BASH

forge test -vvv

Sources#

AuditVault finding: https://github.com/Auditware/AuditVault/blob/main/findings/63167.md
Original report: https://github.com/sherlock-audit/2025-09-ammplify-judging
Synthetic reduction: test/63167-ammplify-maker-spot-price.sol (local reduction)

Reference: AuditVault finding 63167

Sources & further analysis#

Reproductions & code

Standalone PoC + full trace: 63167-ammplify-maker-spot-price_exp (evm-hack-registry mirror).
AuditVault finding: 63167.

Alerts & third-party analyses

Web3Sec X hacked database: search.
Rekt leaderboard: search.
Solodit incident search: search.

These dashboards index community alerts tweets, post-mortems, and independent write-ups. Reach them through the protocol name above to cross-check this reproduction against other analyses.

Source-level debugger — step opcodes and Solidity in sync