Stack Overflow in Gin with Cockroachdb

When building HTTP services in Go with the Gin framework and using CockroachDB as the backend, a stack overflow can occur in application logic or in the database driver handling, often surfacing as out-of-memory conditions or unbounded recursion during query execution. This risk is heightened when APIs expose endpoints that accept unbounded or poorly validated parameters and then use those parameters in recursive or deeply nested SQL operations against CockroachDB.

Consider an endpoint that traverses a hierarchical org-chart stored in a CockroachDB table. If Gin parses an unchecked id from the URL and passes it into a recursive common table expression (CTE) without depth limiting, an attacker can craft a request that causes the database or Go process to consume excessive stack or heap. For example, a path traversal or IDOR-style loop where parent IDs reference descendants can create cycles that recursive queries follow indefinitely, leading to resource exhaustion that middleBrick detects as a BFLA/Privilege Escalation or Property Authorization risk combined with an unsafe consumption pattern.

Additionally, the interplay between Gin’s context binding and CockroachDB’s SQL handling can expose sensitive data or error details that aid an attacker. If error messages from CockroachDB are returned directly in Gin responses, an attacker can learn schema details or trigger verbose stack traces that may aid in crafting injection or enumeration attacks. middleBrick’s Data Exposure and Input Validation checks highlight cases where database errors or stack traces are leaked, and its LLM/AI Security probes test whether endpoints inadvertently expose system prompts or internal logic that could help an attacker escalate the impact of a stack-related issue.

In practice, this specific combination demands careful control of recursion depth, strict validation of identifiers, and bounded query patterns. middleBrick’s inventory and unsafe consumption checks can identify unbounded loops or missing pagination that, when paired with Cockroachdb, increase the likelihood of stack-related anomalies. By scanning such endpoints, the tool surfaces findings tied to OWASP API Top 10 A05:2023 (Server-Side Request Forgery) and A07:2023 (Identification and Authentication Failures) when stack overflow–prone behaviors expose sensitive data or enable denial of service.

To mitigate stack overflow and resource exhaustion risks when using CockroachDB with Gin, enforce strict input validation, bounded recursion, and safe error handling. Use parameterized queries with explicit limits and avoid unbounded recursive CTEs unless you enforce depth caps at both the application and database layers.

Example: a safe recursive query in CockroachDB with a max depth guard:

-- CockroachDB SQL: bounded hierarchy traversal
WITH RECURSIVE org_path AS (
    SELECT id, parent_id, name, 0 AS depth
    FROM orgs
    WHERE id = $1
    UNION ALL
    SELECT o.id, o.parent_id, o.name, op.depth + 1
    FROM orgs o
    INNER JOIN org_path op ON o.parent_id = op.id
    WHERE op.depth < 10
)
SELECT id, parent_id, name, depth FROM org_path;

In Gin, bind and validate the input ID and maximum depth before using them:

// Go + Gin example with validation and bounded query
package handlers

import (
    "context"
    "net/http"
    "strconv"

    "github.com/gin-gonic/gin"
    "github.com/lib/pq"
)

type OrgNode struct {
    ID       int    `json:"id"`
    ParentID *int   `json:"parent_id"`
    Name     string `json:"name"`
    Depth    int    `json:"depth"`
}

func GetOrgHierarchy(c *gin.Context) {
    idParam := c.Query("id")
    if idParam == "" {
        c.JSON(http.StatusBadRequest, gin.H{"error": "missing id"})
        return
    }
    id, err := strconv.Atoi(idParam)
    if err != nil || id <= 0 {
        c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
        return
    }

    maxDepth := 10
    if d := c.Query("max_depth"); d != "" {
        if v, err := strconv.Atoi(d); err == nil && v > 0 && v <= 50 {
            maxDepth = v
        }
    }

    rows, err := db.Query(context.Background(),
        `WITH RECURSIVE org_path AS (
            SELECT id, parent_id, name, 0 AS depth
            FROM orgs
            WHERE id = $1
            UNION ALL
            SELECT o.id, o.parent_id, o.name, op.depth + 1
            FROM orgs o
            INNER JOIN org_path op ON o.parent_id = op.id
            WHERE op.depth < $2
        )
        SELECT id, parent_id, name, depth FROM org_path`, id, maxDepth)
    if err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error": "unable to fetch hierarchy"})
        return
    }
    defer rows.Close()

    var nodes []OrgNode
    for rows.Next() {
        var n OrgNode
        if err := rows.Scan(&n.ID, &n.ParentID, &n.Name, &n.Depth); err != nil {
            c.JSON(http.StatusInternalServerError, gin.H{"error": "data error"})
            return
        }
        nodes = append(nodes, n)
    }
    if err := rows.Err(); err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error": "database error"})
        return
    }
    c.JSON(http.StatusOK, nodes)
}

Additionally, configure Gin to avoid exposing detailed errors in production and use middleware that enforces request size limits to reduce the surface for abusive payloads that could contribute to stack-related conditions. middleBrick’s GitHub Action can be added to CI/CD to fail builds if endpoints lack these guards, while the Web Dashboard tracks scores and the MCP Server lets you scan APIs directly from your AI coding assistant to surface such issues during development.