Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
CWE-566 Variant Incomplete
Authorization Bypass Through User-Controlled SQL Primary Key
This vulnerability occurs when an application allows a user to directly control the primary key value used in a SQL query, enabling them to access database records they are not authorized to view.
Definition
What is CWE-566?
This vulnerability occurs when an application allows a user to directly control the primary key value used in a SQL query, enabling them to access database records they are not authorized to view.
This flaw typically unfolds in three steps: first, user-supplied data from an untrusted source (like a URL parameter or form field) is accepted without proper validation. Second, this data is directly used to specify a primary key in a SQL statement, such as in a `WHERE` clause. Finally, because the database query does not enforce additional row-level permissions, the user can manipulate the key to retrieve or modify records belonging to other users, effectively bypassing the application's intended authorization checks.
Preventing this requires implementing proper access control at the data layer, such as adding checks to ensure the requested record belongs to the current user's session. Managing this at scale is difficult; an ASPM like Plexicus can help you track and remediate these authorization flaws across your entire stack by correlating user flows with data access patterns.
Real-world impact
Real-world CVEs caused by CWE-566
No public CVE references are linked to this CWE in MITRE's catalog yet.
How attackers exploit it
Step-by-step attacker path
- 1
Identify a code path that handles untrusted input without validation.
- 2
Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.
- 3
Deliver the payload through a normal request and observe the application's reaction.
- 4
Iterate until the response leaks data, executes attacker code, or escalates privileges.
Vulnerable code example
Vulnerable C#
The following code uses a parameterized statement, which escapes metacharacters and prevents SQL injection vulnerabilities, to construct and execute a SQL query that searches for an invoice matching the specified identifier [1]. The identifier is selected from a list of all invoices associated with the current authenticated user.
...
conn = new SqlConnection(_ConnectionString);
conn.Open();
int16 id = System.Convert.ToInt16(invoiceID.Text);
SqlCommand query = new SqlCommand( "SELECT * FROM invoices WHERE id = @id", conn);
query.Parameters.AddWithValue("@id", id);
SqlDataReader objReader = objCommand.ExecuteReader();
... Secure code example
Secure pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
const safe = validateAndEscape(input);
return executeWithGuards(safe);
} What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist
How to prevent CWE-566
- Implementation Assume all input is malicious. Use a standard input validation mechanism to validate all input for length, type, syntax, and business rules before accepting the data. Use an "accept known good" validation strategy.
- Implementation Use a parameterized query AND make sure that the accepted values conform to the business rules. Construct your SQL statement accordingly.
Detection signals
How to detect CWE-566
CWE-566
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Frequently asked questions What is CWE-566?
How serious is CWE-566?
What languages or platforms are affected by CWE-566?
How can I prevent CWE-566?
How does Plexicus detect and fix CWE-566?
Where can I learn more about CWE-566?
Frequently asked questions
What is CWE-566?
This vulnerability occurs when an application allows a user to directly control the primary key value used in a SQL query, enabling them to access database records they are not authorized to view.
How serious is CWE-566?
MITRE has not published a likelihood-of-exploit rating for this weakness. Treat it as medium-impact until your threat model proves otherwise.
What languages or platforms are affected by CWE-566?
MITRE lists the following affected platforms: SQL, Database Server.
How can I prevent CWE-566?
Assume all input is malicious. Use a standard input validation mechanism to validate all input for length, type, syntax, and business rules before accepting the data. Use an "accept known good" validation strategy. Use a parameterized query AND make sure that the accepted values conform to the business rules. Construct your SQL statement accordingly.
How does Plexicus detect and fix CWE-566?
Plexicus's SAST engine matches the data-flow signature for CWE-566 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.
Where can I learn more about CWE-566?
MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/566.html. You can also reference OWASP and NIST documentation for adjacent guidance.
Ready to validate what matters?
Ready to validate what matters?
Plexicus is Proof-Driven AppSec: validated findings, contextual understanding, and reviewed remediation — anchored in evidence, scoped with you.