[5.2.x] Fixed CVE-2025-13372 -- Protected FilteredRelation against SQL injection in column aliases on PostgreSQL.

Follow-up to CVE-2025-57833.

Thanks Stackered for the report, and Simon Charette and Mariusz Felisiak
for the reviews.

Backport of 5b90ca1e75 from main.

django/db/backends/postgresql/compiler.py

@@ -1,6 +1,6 @@
 from django.db.models.sql.compiler import (
     SQLAggregateCompiler,
-    SQLCompiler,
+    SQLCompiler as BaseSQLCompiler,
     SQLDeleteCompiler,
 )
 from django.db.models.sql.compiler import SQLInsertCompiler as BaseSQLInsertCompiler
@@ -25,6 +25,15 @@ class InsertUnnest(list):
         return "UNNEST(%s)" % ", ".join(self)
 
 
+class SQLCompiler(BaseSQLCompiler):
+    def quote_name_unless_alias(self, name):
+        if "$" in name:
+            raise ValueError(
+                "Dollar signs are not permitted in column aliases on PostgreSQL."
+            )
+        return super().quote_name_unless_alias(name)
+
+
 class SQLInsertCompiler(BaseSQLInsertCompiler):
     def assemble_as_sql(self, fields, value_rows):
         # Specialize bulk-insertion of literal values through UNNEST to

docs/releases/4.2.27.txt

@@ -7,6 +7,14 @@ Django 4.2.27 release notes
 Django 4.2.27 fixes one security issue with severity "high", one security issue
 with severity "moderate", and one bug in 4.2.26.
 
+CVE-2025-13372: Potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL
+============================================================================================
+
+:class:`.FilteredRelation` was subject to SQL injection in column aliases,
+using a suitably crafted dictionary, with dictionary expansion, as the
+``**kwargs`` passed to :meth:`.QuerySet.annotate` or :meth:`.QuerySet.alias` on
+PostgreSQL.
+
 Bugfixes
 ========
 

docs/releases/5.1.15.txt

@@ -7,6 +7,14 @@ Django 5.1.15 release notes
 Django 5.1.15 fixes one security issue with severity "high", one security issue
 with severity "moderate", and one bug in 5.1.14.
 
+CVE-2025-13372: Potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL
+============================================================================================
+
+:class:`.FilteredRelation` was subject to SQL injection in column aliases,
+using a suitably crafted dictionary, with dictionary expansion, as the
+``**kwargs`` passed to :meth:`.QuerySet.annotate` or :meth:`.QuerySet.alias` on
+PostgreSQL.
+
 Bugfixes
 ========
 

docs/releases/5.2.9.txt

@@ -7,6 +7,14 @@ Django 5.2.9 release notes
 Django 5.2.9 fixes one security issue with severity "high", one security issue
 with severity "moderate", and several bugs in 5.2.8.
 
+CVE-2025-13372: Potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL
+============================================================================================
+
+:class:`.FilteredRelation` was subject to SQL injection in column aliases,
+using a suitably crafted dictionary, with dictionary expansion, as the
+``**kwargs`` passed to :meth:`.QuerySet.annotate` or :meth:`.QuerySet.alias` on
+PostgreSQL.
+
 Bugfixes
 ========
 

tests/annotations/tests.py

@@ -1507,3 +1507,14 @@ class AliasTests(TestCase):
         )
         with self.assertRaisesMessage(ValueError, msg):
             Book.objects.alias(**{crafted_alias: FilteredRelation("authors")})
+
+    def test_alias_filtered_relation_sql_injection_dollar_sign(self):
+        qs = Book.objects.alias(
+            **{"crafted_alia$": FilteredRelation("authors")}
+        ).values("name", "crafted_alia$")
+        if connection.vendor == "postgresql":
+            msg = "Dollar signs are not permitted in column aliases on PostgreSQL."
+            with self.assertRaisesMessage(ValueError, msg):
+                list(qs)
+        else:
+            self.assertEqual(qs.first()["name"], self.b1.name)