CVE-2023-42806 json
Snapshot signature not including HeadID will allow replay attacks
published 2023-09-21 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-47232
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 44%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- iohk hydra 0.13.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 y ago
Exploit prediction
0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H |
Affected products
- input-output-hk hydra
Classification
- Weakness
-
- CWE-347 Improper Verification of Cryptographic Signature
References
-
github.com
/input-output-hk/hydra/security/advisories/GHSA-gr36-mc6v-72qq
vendor-advisory
-
github.com
/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-node/src/Hydra/HeadLogic.hs#L357
product
-
github.com
/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-node/src/Hydra/Snapshot.hs#L50-L54
product
-
github.com
/input-output-hk/hydra/blob/ec6c7a2ab651462228475d0b34264e9a182c22bb/hydra-plutus/src/Hydra/Contract/Head.hs#L
product
Sources
- CVE List CVE-2023-42806
- NVD CVE-2023-42806
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