Yield Ninja withdraw accounting — AuditVault 19123

Source & credit. Reproduction of a public audit finding curated by AuditVault — the original finding: 19123. Standalone Foundry PoC and full write-up: 19123-yield-ninja-withdraw-accounting_exp in the evm-hack-registry mirror.

Vulnerability classes: vuln/logic/incorrect-state-transition · vuln/arithmetic/precision-loss

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

Key info#

Field	Value
Protocol	Audit finding 19123
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/19123-yield-ninja-withdraw-accounting.sol`
Attack contract	`Exploit`
Compiler	Solidity 0.8.24
Reproduction	Local reduced model

TL;DR#

withdraw burns shares but fails to debit the corresponding assets.

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/19123-yield-ninja-withdraw-accounting.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/19123.md
Original report: https://github.com/solodit/solodit_content/blob/main/reports/Pashov/2022-11-01-Yield Ninja.md
Synthetic reduction: test/19123-yield-ninja-withdraw-accounting.sol (local reduction)

Reference: AuditVault finding 19123

Sources & further analysis#

Reproductions & code

Standalone PoC + full trace: 19123-yield-ninja-withdraw-accounting_exp (evm-hack-registry mirror).
AuditVault finding: 19123.

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