PyPi: Tuf

CVE-2021-41131

Safety vulnerability ID: 42183

This vulnerability was reviewed by experts

The information on this page was manually curated by our Cybersecurity Intelligence Team.

Created at Oct 19, 2021 Updated at Oct 07, 2024
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Advisory

Tuf version 0.19 includes a fix for CVE-2021-41131: 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.
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.
https://github.com/theupdateframework/python-tuf/security/advisories/GHSA-wjw6-2cqr-j4qr
https://github.com/theupdateframework/python-tuf/commit/4ad7ae48fda594b640139c3b7eae21ed5155a102
https://github.com/theupdateframework/python-tuf/issues/1527

Affected package

tuf

Latest version: 5.1.0

A secure updater framework for Python

Affected versions

Fixed versions

Vulnerability changelog

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. See CVE-2021-41131.


CONFIRM:https://github.com/theupdateframework/python-tuf/security/advisories/GHSA-wjw6-2cqr-j4qr: https://github.com/theupdateframework/python-tuf/security/advisories/GHSA-wjw6-2cqr-j4qr
MISC:https://github.com/theupdateframework/python-tuf/commit/4ad7ae48fda594b640139c3b7eae21ed5155a102: https://github.com/theupdateframework/python-tuf/commit/4ad7ae48fda594b640139c3b7eae21ed5155a102
MISC:https://github.com/theupdateframework/python-tuf/issues/1527: https://github.com/theupdateframework/python-tuf/issues/1527

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Severity Details

CVSS Base Score

HIGH 8.7

CVSS v3 Details

HIGH 8.7
Attack Vector (AV)
NETWORK
Attack Complexity (AC)
HIGH
Privileges Required (PR)
NONE
User Interaction (UI)
NONE
Scope (S)
CHANGED
Confidentiality Impact (C)
NONE
Integrity Impact (I)
HIGH
Availability Availability (A)
HIGH

CVSS v2 Details

HIGH 8.8
Access Vector (AV)
NETWORK
Access Complexity (AC)
MEDIUM
Authentication (Au)
NONE
Confidentiality Impact (C)
NONE
Integrity Impact (I)
COMPLETE
Availability Impact (A)
COMPLETE