Incorrect threshold signature computation in TUF
Impact
Metadadata signature verification, as used in tuf.client.updater, counted each of multiple signatures with identical authorized keyids separately towards the threshold. Therefore, an attacker with access to a valid signing key could create multiple valid signatures in order to meet the minimum threshold of keys before the metadata was considered valid.
The tuf maintainers would like to thank Erik MacLean of Analog Devices, Inc. for reporting this issue.
Patches
A fix is available in version 0.12.2 or newer.
Workarounds
No workarounds are known for this issue.
References
- CVE-2020-6174
- Pull request resolving the issue PR 974
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | tuf | < 0.12.2 | 0.12.2 |
References
- https://github.com/theupdateframework/tuf/pull/974
- https://github.com/advisories/GHSA-pwqf-9h7j-7mv8
- https://github.com/theupdateframework/tuf/security/advisories/GHSA-pwqf-9h7j-7mv8
- https://nvd.nist.gov/vuln/detail/CVE-2020-6174
- https://github.com/theupdateframework/python-tuf/commit/2977188139d065ff3356c3cb4aec60c582b57e0e
- https://github.com/pypa/advisory-database/tree/main/vulns/tuf/PYSEC-2020-147.yaml
- https://github.com/theupdateframework/tuf
- https://github.com/theupdateframework/tuf/releases/tag/v0.12.2
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-347- Platform
- Python (PyPI)
- Package
tuf- Disclosed
- 05.02.2020
- Updated
- 11.10.2026 11:20
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2020-147 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-pwqf-9h7j-7mv8 - CC BY 4.0
Vulnerability history: tuf
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 7
- First → latest
- 01.2020 05.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- Medium 4
- Low 2
Disclosures per year
- 2020: 3
- 2021: 1
- 2022: 1
- 2023: 0
- 2024: 1
- 2025: 0
- 2026: 1
-
Incorrect threshold signature computation in TUF this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.