GHSA-r3hx-x5rh-p9vv: django-haystack: Remote Code Execution via `eval()` in Elasticsearch Result Deserialization

Remote Code Execution via eval() in Elasticsearch Result Deserialization Summary The Elasticsearch backend in django-haystack calls eval() on raw field values returned from Elasticsearch when a SearchField is declared with an index_fieldname alias that differs from the logical field name. During result processing, the backend looks up fields by logical name but Elasticsearch stores them under the alias key; the lookup fails and the value falls through to _to_python() → eval(). An attacker who can control content that is indexed into Elasticsearch—and can trigger or wait for a search that returns it—achieves arbitrary code execution in the Django application process. CVSS 3.1 Base Score: 8.5 (High). Details **Sink — haystack/backends/elasticsearch_backend.py:865:** converted_value = eval(value) _to_python() (line ~850) attempts to parse a string value by calling eval() before performing any type-safety check. If the value is an attacker-controlled Python expression such as import('os').system(...), the expression is executed unconditionally. **Root cause — haystack/backends/elasticsearch_backend.py:727–737:** for key, value in source.items(): string_key = str(key) if string_key in index.fields and hasattr(index.fields[string_key], "convert"): additional_fields[string_key] = index.fields[string_key].convert(value) else: additional_fields[string_key] = self._to_python(value) index.fields is keyed by the *logical* field name (e.g. "name"), but Elasticsearch stores the document under the index_fieldname alias (e.g. "name_s"). Because "name_s" not in index.fields, the branch falls through to self._to_python(value). Data flow (source → sink): 1. haystack/indexes.py:226 — self.prepared_data[field.index_fieldname] = field.prepare(obj) stores data under the alias. 2. haystack/backends/elasticsearch_backend.py:218 — prepared data copied into final_data. 3. haystack/backends/elasticsearch_backend.py:236 — bulk(...) writes the document to Elasticsearch under the alia