Ssrf in Gin with Cockroachdb

Server-Side Request Forgery (SSRF) in a Gin application that uses CockroachDB can occur when user-supplied input is used to construct HTTP requests or database connection parameters without adequate validation. In this stack, an attacker may trick the server into making arbitrary internal or external requests, potentially reaching the CockroachDB HTTP admin UI or metadata services that are accessible from the application environment.

Consider a scenario where Gin dynamically builds a database connection string based on a user-provided hostname or port. If the application does not validate or sanitize these inputs, an attacker can supply an internal address such as http://localhost:8080 (where CockroachDB's admin UI might be exposed) or a cloud metadata endpoint. Because the application runs with network access to the database, the SSRF vector can become a path to reconnaissance or privilege escalation within the cluster.

Insecure code pattern:

// Gin handler that builds a CockroachDB connection string from user input
func connectHandler(c *gin.Context) {
    host := c.Query("host")
    port := c.Query("port")
    connStr := fmt.Sprintf("postgresql://root@%s:%s?sslmode=disable", host, port)
    db, err := gorm.Open(postgres.Open(connStr), &gorm.Config{})
    if err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
        return
    }
    // Use db...
    c.JSON(200, gin.H{"status": "connected"})
}

If an attacker sends host=169.254.169.254 and port=8080, the application may make requests to the cloud metadata service or to an internal CockroachDB admin endpoint, depending on deployment topology. Because CockroachDB often exposes an administrative interface on a local port when not properly firewalled, SSRF can expose sensitive cluster information or allow lateral movement within a private network.

Another vector involves outbound HTTP requests initiated by the backend, such as fetching schema or configuration from a user-defined URL. If the URL points to an internal CockroachDB SQL proxy or status endpoint, the request may be interpreted as trusted internal traffic, bypassing network-level restrictions.

Because middleBrick tests unauthenticated attack surfaces, SSRF findings often highlight endpoints that accept URLs or network destinations without strict allowlists or URL parsing safeguards. This stack is especially sensitive when endpoints expose database diagnostics or when network segmentation is weak.

Remediation focuses on input validation, network segmentation, and avoiding dynamic connection strings based on untrusted data. For CockroachDB, prefer static connection parameters and enforce strict network policies.

Secure Gin handler with validation and static connection:

// Validate host against an allowlist and use a fixed CockroachDB connection
var allowedHosts = map[string]bool{
    "cockroachdb-internal.default.svc.cluster.local": true,
}

func secureConnectHandler(c *gin.Context) {
    host := c.Query("host")
    if !allowedHosts[host] {
        c.JSON(http.StatusBadRequest, gin.H{"error": "host not allowed"})
        return
    }
    // Use a fixed port and TLS for CockroachDB
    connStr := "postgresql://[email protected]:26257?sslmode=verify-full&sslrootcert=/etc/certs/ca.pem"
    db, err := gorm.Open(postgres.Open(connStr), &gorm.Config{})
    if err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error": "database unavailable"})
        return
    }
    c.JSON(200, gin.H{"status": "securely connected"})
}

Key practices:

• Do not concatenate user input into connection strings. Use environment variables or configuration files for database endpoints.
• Enforce network policies so that the application pod can only reach known CockroachDB service endpoints.
• Use TLS with certificate verification (sslmode=verify-full) and reference certificates stored as Kubernetes secrets or mounted files.
• Disable unnecessary HTTP administrative interfaces in CockroachDB deployments and restrict access to internal networks only.
• Implement request-level allowlists for any user-controlled parameters that influence network calls, and reject private IP ranges (127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) and cloud metadata IPs.

For applications that must fetch external schemas or configurations, use a proxy with strict allowlisting rather than direct user-supplied URLs. middleBrick can help identify endpoints that remain vulnerable to SSRF by testing unauthenticated surfaces and mapping findings to frameworks such as OWASP API Top 10 and compliance controls.