vulnerability / NVI-00016238 / Revision 1
python-multipart: Content-Disposition parameter smuggling via RFC 2231/5987 extended parameters
GitHub lists this reviewed advisory for python-multipart. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
3.7 low
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
python-multipart
source listed< 0.0.30
### Summary `parse_options_header` parsed `Content-Disposition` (and `Content-Type`) headers with `email.message.Message`, which transparently applies RFC 2231/5987 decoding. The extended parameter syntax (`filename*=charset'lang'value`, `name*=...`, and the `filename*0`/`filename*1` continuation form) is decoded and surfaced under the bare `filename`/`name` key, and overrides the plain parameter when both are present. RFC 7578 §4.2 explicitly forbids the `filename*` form in `multipart/form-data`. Components that follow RFC 7578, or that do not implement RFC 2231/5987 decoding for `multipart/form-data` (WAFs, proxies, gateways), may interpret such a header differently. An attacker can exploit that difference to smuggle a different field name or filename past an upstream inspector to the backend. ### Details Given both a plain and an extended parameter, the extended value won. For example: ``` Content-Disposition: form-data; name="comme
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-vffw-93wf-4j4q ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.