Taurus multi-party-sig has OT-based ECDSA protocol implementation flaws

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Coinbase researchers reported 2 security issues in our implementation of the oblivious transfer (OT) based protocol DKLS: 1. Secret share recovery attack If the base OT setup of the protocol is reused for another execution of the OT extension, then a malicious participant can extract a bit of the secret of another participant. By repeating the execution they can eventually recover the whole secret. Therefore, unlike our comments suggested, you must not reuse an OT setup for multiple protocol executions. We're adding a warning in the code: https://github.com/taurushq-io/multi-party-sig/blob/9e4400fccee89be6195d0a12dd0ed052288d5040/internal/ot/extended.go#L114 2. Invalid security proof due to incorrect operator The original 2018 version of the DKLS had a typo in the OT extension protocol when computing the check value in the OT extension: the paper noted a XOR whereas it should be a field multiplication. This erroneous behavior was implemented in our code. The proof of security fails…

Published by the source

25 Nov 2024, 15:11 UTC

Last modified by the source

28 Jan 2025, 18:06 UTC

Source last checked

26 Oct 2026, 15:08 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-7f6p-phw2-8253

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# Patch Next advisory brief: GHSA-7f6p-phw2-8253

Advisory: Taurus multi-party-sig has OT-based ECDSA protocol implementation flaws
IDs: GHSA-7f6p-phw2-8253
Record: https://patchnext.com/advisories/ghsa-7f6p-phw2-8253 (revision 1, source checked 26 Oct 2026, 15:08 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/taurusgroup/multi-party-sig 0.7.0-alpha-2025-01-28. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/taurusgroup/multi-party-sig: affected <= 0.6.0-alpha-2021-09-21; fixed in 0.7.0-alpha-2025-01-28

## Suggested inspection (read-only)
- Go github.com/taurusgroup/multi-party-sig: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/taurusgroup/multi-party-sig.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-7f6p-phw2-8253 (GitHub-reviewed advisory GHSA-7f6p-phw2-8253 lists affected ranges: Go github.com/taurusgroup/multi-party-sig >=0 <=0.6.0-alpha-2021-09-21)

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