Executive brief
The Update Framework (TUF) is a metadata framework used by software repositories to ensure secure package distribution. An attacker with file write access to the repository can cause client applications to experience significant delays (minutes or longer) by injecting many invalid signatures into metadata files, forcing clients to verify each one before detecting the invalidity.
Technical details
This vulnerability is a denial of service issue in the TUF client signature verification process (CWE-400: Uncontrolled Resource Consumption). An attacker who gains write access to the repository metadata can create metadata files with a large number of invalid signatures. The vulnerable TUF client will attempt to verify each signature sequentially, delaying the moment when it determines that all signatures are invalid. This delay can extend to minutes or longer, particularly when multiple metadata files are affected. The attack requires repository file access; no network exploitation or user interaction is needed. No patch has been released for this issue.
Affected products
- The Update Framework TUF 0.7.2 through 0.12.1
Timeline
- 2020-08-21: disclosed