datamodel-code-generator generates Pydantic v2 models, dataclasses, TypedDict, and msgspec.Struct from OpenAPI, JSON Schema, GraphQL, Avro, Protobuf, and raw JSON, YAML, or CSV. Prior to 0.63.0, datamodel-code-generator validates a URL host once in src/datamodel_code_generator/http.py through get_body, _validate_url_for_fetch, and _get_ips_from_host, but then lets httpx resolve the host again for the connection, allowing DNS rebinding to bypass allow_private_network=False and reach internal services. This issue is fixed in version 0.63.0.
Weakness
The product performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Datamodel-code-generator | Koxudaxi | * | 0.63.0 (excluding) |
Extended Description
Since DNS names can be easily spoofed or misreported, and it may be difficult for the product to detect if a trusted DNS server has been compromised, DNS names do not constitute a valid authentication mechanism. When the product performs a reverse DNS resolution for an IP address, if an attacker controls the DNS server for that IP address, then the attacker can cause the server to return an arbitrary hostname. As a result, the attacker may be able to bypass authentication, cause the wrong hostname to be recorded in log files to hide activities, or perform other attacks. Attackers can spoof DNS names by either (1) compromising a DNS server and modifying its records (sometimes called DNS cache poisoning), or (2) having legitimate control over a DNS server associated with their IP address.
Potential Mitigations
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/142.html
- https://cwe.mitre.org/data/definitions/275.html
- https://cwe.mitre.org/data/definitions/73.html
- https://cwe.mitre.org/data/definitions/89.html
References
- https://github.com/koxudaxi/datamodel-code-generator/commit/25c8b7e497419eb20b230fa3318c04f9bebc5a6f
- https://github.com/koxudaxi/datamodel-code-generator/releases/tag/0.63.0
- https://github.com/koxudaxi/datamodel-code-generator/security/advisories/GHSA-vx7x-vcc2-c44g
- https://gist.github.com/thegr1ffyn/c1d54dd6ff2a4c0d7d0dabe00c4985f4