Improper verification of signature threshold in tough

## Impact The tough library, prior to 0.7.1, does not properly verify the uniqueness of keys in the signatures provided to meet the threshold of cryptographic signatures. It allows someone with access to a valid signing key to create multiple valid signatures in order to circumvent TUF requiring a minimum threshold of unique keys before the metadata is considered valid. AWS would like to thank Erick Tryzelaar of the Google Fuchsia Team for reporting this issue. ## Patches A fix is available in version 0.7.1. ## Workarounds No workarounds to this issue are known. ## References CVE-2020-6174 is assigned to the same issue in the TUF reference implementation. https://github.com/theupdateframework/tuf/pull/974 https://nvd.nist.gov/vuln/detail/CVE-2020-6174 ## For more information If you have any questions or comments about this advisory, [contact AWS Security](https://aws.amazon.com/security/vulnerability-reporting/) at [[email protected]](mailto:[email protected]).

Source published

25 Aug 2021 20:56:55 UTC

Source modified

8 Jul 2026 06:29:16 UTC

Observed here

24 Oct 2026 13:19:54 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Publisher rating · HIGH