Entity Framework Core (EF Core) is a widely used Object Relational Mapping (ORM) for .NET; but its convenience can hide subtle risks. 

Mistakes in query composition, secrets management, model binding, or migrations create opportunities for attackers. This article surveys the common attack surface around EF Core and gives practical, defensible countermeasures you can apply today.

The Attack Surface

EF Core reduces direct Structured Query Language (SQL) writing; but still interacts with SQL engines and the Operating System (OS) environment.

Typical attackers would leverage improper use of raw SQL Application Programming Interface (API) leading to an entry point, using SQL injection. Another would be overposting, mass-assignment via model binding that allows privilege escalation or data corruption.

Leaked connection strings or secrets giving direct Database (DB) access, misconfigured migrations or privileged DB accounts allow schema or time-of-run misuse. Poor logging and monitoring will allow attackers to persist longer without detection.

SQL Injection Risks

EF Core’s Language Integrated Query (LINQ) inherently employs parameterization, rendering it secure under standard usage conditions.

Consequently, developers are advised to prioritize LINQ for data access operations whenever feasible. Security vulnerabilities typically arise from improper implementation of raw SQL interfaces. In scenarios where direct SQL execution is unavoidable, the recommended approach is to utilize the FromSqlInterpolated method or a parameterized FromSqlRaw invocation with explicitly defined DbParameter objects, ensuring that user-supplied input is consistently treated as data rather than executable code.

Both Microsoft and the broader EF Core development community emphasize that FromSqlInterpolated and FromSql methods incorporate parameterization safely, whereas misuse of FromSqlRaw—particularly through string concatenation—may introduce exploitable SQL injection vulnerabilities.

Accordingly, any form of concatenated SQL should be regarded as inherently suspect and subject to rigorous validation.

Overposting Pitfalls

When controllers bind incoming JavaScript Object Notation (JSON) or form data directly into EF entities, attackers can set fields they shouldn’t.

To defend yourself against this you should use Data Transfer Objects (DTO) / View Models for incoming data and map to entities explicitly, this decouples external input model from the database model. Avoid mass-binding to entity types in HTTP POST/PUT handlers, use attributes sparingly; mapping DTO to entity is clearer and safer. Validate model state and enforce allowed fields from server-side and log any suspicious attempts.

Secrets Management

Hard-coded connection strings or credentials in source code or config files are a major risk: once leaked, an attacker can query the DB directly.

To avoid this, follow best practices like using secrets stores, limit privileges of the database account used by the app, adhere to least privilege principle, rotate credentials and use managed identities where possible.

Migration and Deployment Hygiene

EF Core migrations possess the capability to execute Data Definition Language (DDL) operations during application startup. When combined with elevated database privileges, this functionality may create conditions under which a compromise of the application’s runtime environment could allow an attacker to modify the database schema or escalate privileges.

To mitigate such risks, migrations should be executed within a controlled Continuous Integration and Continuous Delivery/Deployment (CI/CD) pipeline rather than invoking DbContext.Database.Migrate() method ;automatically in production. Distinct database accounts should be designated for schema modifications and for routine application operations, adhering to the principle of least privilege.

Furthermore, migration credentials must be securely stored within the deployment pipeline—never within the running application—and all migration scripts should undergo formal review and validation, with backups and rollback procedures in place prior to execution.

Logging, Auditing, and Detection

EF Core exposes query logging — use it carefully by logging at the appropriate levels, avoid logging sensitive data and enable database auditing to help detect suspicious activity.

Remember to correlate application logs with database logs and use anomaly detection or Intrusion Detection System (IDS) where feasible. Good observability shortens attacker’s dwell time and helps with incident response.

Dependency Hygiene & Patches

Keep EF Core and related packages up to date. Vulnerabilities can appear in the runtime or in database drivers, use automated dependency scanning and subscribe to vendor security announcements.

Additional Hardening Recommendations

Use parameterized stored procedures for very sensitive queries and wrap them with least-privilege accounts. Always try to avoid dynamic SQL built from user input, if dynamic filters are needed, build expressions safely rather than string concatenation. Apply row-level security features of your DBMS where appropriate, encrypt sensitive columns and enforce TLS for DB connections.

Testing and Threat Modeling

Include EF Core scenarios in threat models and code reviews, run static analysis and dynamic tests against your app and ensure you test for SQL injection, overposting, and access-control bypasses in controlled environments only.

When doing penetration testing or research, operate under authorization and avoid publishing actionable exploit steps.

Conclusion

Entity Framework Core simplifies data access but is not a magic bullet for security. The majority of EF Core-related incidents stem from developer patterns; raw SQL concatenation, mass-assignment, secrets leakage rather than the ORM itself.

Prioritize high-level LINQ queries instead of raw SQL, use DTO-based binding, enforce least-privilege database access, safeguard secrets properly, and maintain strong observability to significantly reduce security risks.