Vulnerability · Published Sep 21, 2023 · Assigned by GitHub_M
CVE-2023-42806Snapshot signature not including HeadID will allow replay attacks
Medium 6.5
In plain English
A medium-severity security flaw in hydra from input-output-hk. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities).
Official description
Hydra is the layer-two scalability solution for Cardano. Prior to version 0.13.0, not signing and verifying `$\mathsf{cid}$` allows an attacker (which must be a participant of this head) to use a snapshot from an old head instance with the same participants to close the head or contest the state with it. This can lead to an incorrect distribution of value (= value extraction attack; hard, but possible) or prevent the head to finalize because the value available is not consistent with the closed utxo state (= denial of service; easy). A patch is planned for version 0.13.0. As a workaround, rotate keys between heads so not to re-use keys and not result in the same multi-signature participants.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| input-output-hk | hydra | < 0.13.0 |
Weakness: CWE-347 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
References
- https://github.com/input-output-hk/hydra/security/advisories/GHSA-gr36-mc6v-72qq x_refsource_CONFIRM
- https://github.com/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-node/src/Hydra/HeadLogic.hs#L357 x_refsource_MISC
- https://github.com/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-node/src/Hydra/Snapshot.hs#L50-L54 x_refsource_MISC
- https://github.com/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-plutus/src/Hydra/Contract/Head.hs#L583-L599 x_refsource_MISC