Renzo — incorrect withdraw queue balance in TVL calculation

Source & credit. Reproduction of a public audit finding curated by AuditVault — the original finding: 33495-h-08-incorrect-withdraw-queue-balance-in-tvl-calculation-cod. Standalone Foundry PoC and full write-up: 33495-h-08-incorrect-withdraw-queue-balance-in-tvl-calculation-cod_exp in the evm-hack-registry mirror.

Vulnerability classes: precision-loss · data-corruption/price-manipulation

Reproduction: a self-contained Foundry PoC that compiles & runs in an isolated project with only forge-std — no fork, no RPC, no anvil_state. Full trace: output.txt. PoC: test/33495-h-08-incorrect-withdraw-queue-balance-in-tvl-calculation-cod_exp.sol.

Key info#


Impact	HIGH — withdraw-queue TVL uses the wrong collateral index, understating TVL and minting excess shares
Protocol	Renzo
Vulnerable code	`RestakeManager`
Bug class	precision-loss
Finding	Code4rena — Renzo, 2024-04 · #33495 · reporter josephdara
Report	code4rena.com/reports/2024-04-renzo
Source	AuditVault
Status	Audit finding — caught in review, not exploited on-chain. Reproduced as a standalone local PoC.
Compiler	`^0.8.24` (PoC)

This is an audit finding, not a historical on-chain incident. The PoC keeps the vulnerable logic verbatim (marked @> VULN) and reduces dependencies to the minimum needed to show the claimed harm.

TL;DR#

TVL loops ODs (i) then collateral tokens (j).
Withdraw-queue oracle call uses collateralTokens[i] for price but balanceOf token j.
With 1 OD and 3 tokens, token0 is priced 3×; tokens 1/2 ignored.
Deposit against understated TVL mints excess shares.

The vulnerable code#

See test/33495-h-08-incorrect-withdraw-queue-balance-in-tvl-calculation-cod.sol — the @> VULN marker is on the blamed line (line 98 in the synthetic).

Root cause#

Wrong loop index on the oracle token identity for the withdraw-queue contribution.

Preconditions#

Protocol operating conditions that make the path reachable (see finding report). No exotic privileges beyond those the real call path requires.

Attack walkthrough#

From output.txt: the Exploit.run() path executes the attack end-to-end and requires the harm.

Diagrams#

flowchart TD A[Setup reduced protocol state] --> B[Trigger vulnerable path] B --> C[VULN line executes] C --> D[Harm asserted]

Impact#

Miscalculated TVL drives mint/redeem; excess shares dilute honest LPs.

Sources#

AuditVault finding
Code4rena report
Protocol source: https://github.com/code-423n4/2024-04-renzo

Sources & further analysis#

Reproductions & code

Standalone PoC + full trace: 33495-h-08-incorrect-withdraw-queue-balance-in-tvl-calculation-cod_exp (evm-hack-registry mirror).
AuditVault finding: 33495-h-08-incorrect-withdraw-queue-balance-in-tvl-calculation-cod.

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.

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