CVE-2021-41131

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-traversing role and B) get the role delegated by an existing targets metadata, The written file content is heavily restricted since it needs to be a valid, signed targets file. The file extension is always .json. A fix is available in version 0.19 or newer. There are no workarounds that do not require code changes. Clients can restrict the allowed char