tuf has platform-dependent delegation path matching
`DelegatedRole._is_target_in_pathpattern` uses `fnmatch.fnmatch` to decide whether a given target path is authorized by a delegation's glob pattern.
Python's `fnmatch.fnmatch` calls `os.path.normcase()` on both arguments before matching. On POSIX hosts `normcase` is the identity function; on Windows hosts `os.path` resolves to `ntpath`, whose `normcase` lowercases its input and replaces `/` with `\`.
As a result, python-tuf's delegation *path pattern* matching is case-sensitive on Linux/macOS but case-INSENSITIVE on Windows. This makes the authorization decision for a target dependent on the host operating system of the client running the u
tuf's Metadata API: Targets.get_delegated_role() is missing input validation
The security of both a TUF client and repository implementations depend on the concept of trusted Metadata objects verifying the signatures over other Metadata that it delegates to. This verification process uses `Targets.get_delegated_role(delegated_role: str)` to find the delegation information.
`tuf.api.metadata.Targets.get_delegated_role()` should ensure that the given `delegated_rolename` is actually a name of a role that is delegated by that Targets, but in the case of "succinct delegation" this does not happen.
`tuf.ngclient` users are **not** impacted but direct users of `tuf.api.metadata` could be impacted.
### Impact
If an attac
Python-TUF vulnerable to incorrect threshold signature computation for new root metadata
### Impact
The function `_verify_root_self_signed()`, introduced in [v0.14.0](https://github.com/theupdateframework/tuf/releases/tag/v0.14.0), and which verifies self-signatures in a new root metadata file, counted multiple signatures by any new root key towards the new threshold. That is, any single new root key could theoretically provide enough signatures to meet the threshold for new key self-signatures required during root metadata update.
A scenario where this attack could be relevant is amazingly unlikely in practice to the point where labeling this issue as a security advisory is potentially overstating the impact of the issue. Give
python-tuf is a Python reference implementation of The Update Framework (TUF). In both clients (`tuf/client` and `tuf/ngclient`), there is a path traversal vulnerability that in the worst case can overwrite files ending in `.json` anywhere on the client system on a call to `get_one_valid_targetinfo()`. It occurs because the rolename is used to form the filename, and may contain path traversal characters (ie `../../name.json`). The impact is mitigated by a few facts: It only affects implementations that allow arbitrary rolename selection for delegated targets metadata, The attack requires the ability to A) insert new metadata for the path-trav
Invalid root may become trusted root in The Update Framework (TUF)
Python TUF (The Update Framework) reference implementation before version 0.12 it will incorrectly trust a previously downloaded root metadata file which failed verification at download time. This allows an attacker who is able to serve multiple new versions of root metadata (i.e. by a person-in-the-middle attack) culminating in a version which has not been correctly signed to control the trust chain for future updates. This is fixed in version 0.12 and newer.