Broken Access Control in Echo Go with Dynamodb

Broken Access Control occurs when an API incorrectly enforces permissions, allowing a user to access or modify resources they should not reach. In an Echo Go service that uses Dynamodb as the data store, the risk arises when authorization checks are missing or misapplied before database operations. Because Dynamodb is a low-level, schema-aware key-value store, it does not enforce row-level or attribute-level permissions by itself. If the Go handler builds a Dynamodb request using user-supplied identifiers without validating that the requesting user owns or is allowed to access those identifiers, the API exposes BOLA/IDOR (Broken Level Authorization / Insecure Direct Object Reference) issues.

For example, an endpoint like /users/{userID}/profile might extract userID from the URL, then construct a Dynamodb GetItem key using that ID. If the handler does not confirm that the authenticated subject matches userID, an attacker can change the path parameter to another user’s ID and retrieve or alter another user’s profile. In a typical Echo Go setup with middleware that sets identity into context, failing to propagate and verify the subject against the record’s ownership attribute in Dynamodb leads to authorization bypass. Attack patterns such as IDOR are common in APIs that expose database identifiers without scoping queries to the actor’s tenant or principal.

Additionally, scan workflows that include OpenAPI/Swagger spec analysis help highlight mismatches between declared routes and implemented authorization logic. When the spec describes /users/{id} as accessible without scope or role constraints, but the code lacks per-request checks, the discrepancy becomes an actionable finding. middleBrick tests this attack surface by running 12 security checks in parallel, including BOLA/IDOR and Property Authorization, against the unauthenticated endpoint. This means a developer can receive a finding that flags the missing ownership validation before any sensitive data is exposed, with remediation guidance that emphasizes scoping Dynamodb requests to the authenticated subject.

To fix Broken Access Control in Echo Go when using Dynamodb, always enforce ownership or role-based checks immediately before constructing each database request. Use Echo’s middleware to attach the authenticated subject to the request context, and ensure every Dynamodb operation includes the subject as part of the key condition or filter expression. Below are two concrete examples: one vulnerable pattern and one corrected pattern.

Vulnerable pattern

An endpoint that reads a profile by ID without verifying that the ID belongs to the caller:

// WARNING: Vulnerable — does not validate that profileID belongs to the user
func getProfile(c echo.Context) error {
    profileID := c.Param("profileID")
    svc := dynamodb.NewFromConfig(cfg)
    out, err := svc.GetItem(context.TODO(), &dynamodb.GetItemInput{
        TableName: aws.String("Profiles"),
        Key: map[string]types.AttributeValue{
            "profile_id": &types.AttributeValueMemberS{Value: profileID},
        },
    })
    if err != nil {
        return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
    }
    if out.Item == nil {
        return echo.NewHTTPError(http.StatusNotFound)
    }
    return c.JSON(out.Item)
}

Corrected pattern with ownership scoping

An endpoint that binds the authenticated subject to the Dynamodb key:

func getProfile(c echo.Context) error {
    profileID := c.Param("profileID")
    userID, ok := c.Get("userID").(string) // injected by auth middleware
    if !ok {
        return echo.NewHTTPError(http.StatusUnauthorized, "missing user identity")
    }
    // Ensure the profile belongs to the user
    if !strings.HasPrefix(profileID, userID+"_") {
        return echo.NewHTTPError(http.StatusForbidden, "access denied")
    }
    svc := dynamodb.NewFromConfig(cfg)
    out, err := svc.GetItem(context.TODO(), &dynamodb.GetItemInput{
        TableName: aws.String("Profiles"),
        Key: map[string]types.AttributeValue{
            "profile_id": &types.AttributeValueMemberS{Value: profileID},
            "owner_id":   &types.AttributeValueMemberS{Value: userID},
        },
    })
    if err != nil {
        return echo.NewHTTPError(http.StatusInternalServerError, err.Error())
    }
    if out.Item == nil {
        return echo.NewHTTPError(http.StatusNotFound)
    }
    // Optionally filter attributes in Go to avoid returning sensitive fields
    return c.JSON(out.Item)
}

These patterns ensure that the Dynamodb request is scoped to the authenticated subject, mitigating IDOR. For broader protection across many endpoints, consider integrating the middleBrick CLI (middlebrick scan <url>) to validate that your routes include proper authorization checks. If you need CI/CD enforcement, the GitHub Action can fail builds when findings exceed your risk threshold, and the Pro plan provides continuous monitoring with configurable scans and alerts. Teams using AI-assisted coding can also add the MCP Server to scan APIs directly from the IDE, helping catch missing ownership checks early.

Additionally, align your controls with real standards: Broken Access Control is covered in OWASP API Top 10 A01:2023, and similar mappings appear in PCI-DSS and SOC2. By scoping Dynamodb operations to the authenticated principal and validating input against the actor’s identity, you reduce the likelihood of unauthorized read or write actions.