defirisk.co
rubric v1.7.0

Same-root-cause repeat exploit

Yearn Finance's assessment for RD-F-079 — scored red on the v1.7.0 rubric. The evidence below is the curator's reasoning for this score.

Evidence summary #

Incidents #2 (2023-04-13, yUSDT) and #4 (2023-12-16, iearn TUSD) share identical root cause: legacy immutable iearn contract configured with wrong Fulcrum address since deployment day, never corrected, user funds never migrated. Hacksdatabase yearn-rekt4.md explicitly describes incident #4 as 'a virtual carbon copy of the April 2023 iearn USDT vault bug' with the same configuration error pattern. Two events with identical root-cause cluster = red. Incidents #1 (migration window) and #3 (Newton-Raphson underflow) have distinct root causes.

Sources #

  • URL
    rekt.news — Yearn Finance 4th exploit (2023-12-16)rekt.news yearn-rekt4 — corroborates identical root cause pattern between 2023-04 and 2023-12 incidentsretrieved 2026-05-16
  • Internal
    Yearn Finance 2nd Exploit — wrong Fulcrum address root causehacksdatabase/hacks/yearn2-rekt.md — 2023-04-13 yUSDT Fulcrum-USDC address misconfiguration root causeretrieved 2026-05-16
  • Internal
    Yearn Finance 4th Exploit — identical Fulcrum misconfiguration root causehacksdatabase/hacks/yearn-rekt4.md — 2023-12-16 TUSD vault identical Fulcrum misconfiguration; 'virtual carbon copy' characterizationretrieved 2026-05-16

Methodology #

Determine whether the protocol has been exploited ≥2 times via the same root-cause cluster.

See the full factor methodology and distribution across all protocols →

rubric_version v1.7.0 protocol yearn-finance factor RD-F-079 score red collected_at 2026-05-16 08:34:32