CVE-2021-41131: Path Traversal
First published: Tue Oct 19 2021(Updated: )
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 character set for rolenames, or they can store metadata in files named in a way that is not vulnerable: neither of these approaches is possible without modifying python-tuf.
Credit: security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linuxfoundation The Update Framework | <=0.18.1 |
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Reference Links
Frequently Asked Questions
What is CVE-2021-41131?
CVE-2021-41131 is a path traversal vulnerability in the Python reference implementation of The Update Framework (TUF) in the clients tuf/client and tuf/ngclient, which can allow files ending in .json to be overwritten on the client system.
How severe is CVE-2021-41131?
CVE-2021-41131 has a severity rating of 8.7 out of 10, which is considered high.
How does CVE-2021-41131 affect Python-TUF?
CVE-2021-41131 affects Python-TUF versions up to and including 0.18.1.
How can the path traversal vulnerability in Python-TUF be exploited?
The path traversal vulnerability in Python-TUF can be exploited by manipulating certain input to overwrite files ending in .json on the client system.
Is there a fix for CVE-2021-41131?
Yes, there is a fix for CVE-2021-41131 which is available in the GitHub commit mentioned in the references.
- collector/nvd-index
- vendor/linuxfoundation
- canonical/linuxfoundation the update framework
- version/linuxfoundation the update framework/0.18.1