fix(security): add SSRF protection to URL validation

client/src/utils/__tests__/urlValidation.test.ts

@@ -1,4 +1,4 @@
-import { validateRedirectUrl } from "../urlValidation";
+import { validateRedirectUrl, isPrivateUrl } from "../urlValidation";
 
 describe("validateRedirectUrl", () => {
   describe("valid URLs", () => {
@@ -132,4 +132,148 @@ describe("validateRedirectUrl", () => {
       );
     });
   });
+
+  describe("SSRF protection", () => {
+    it("should block localhost", () => {
+      expect(() => validateRedirectUrl("http://localhost/callback")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should block localhost with port", () => {
+      expect(() =>
+        validateRedirectUrl("http://localhost:3000/callback"),
+      ).toThrow("private/internal address");
+    });
+
+    it("should block 127.0.0.1", () => {
+      expect(() => validateRedirectUrl("http://127.0.0.1/callback")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should block 127.x.x.x range", () => {
+      expect(() => validateRedirectUrl("http://127.0.0.2:8080/")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should block private 10.x.x.x range", () => {
+      expect(() => validateRedirectUrl("http://10.0.0.1/callback")).toThrow(
+        "private/internal address",
+      );
+      expect(() => validateRedirectUrl("http://10.255.255.255/")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should block private 172.16-31.x.x range", () => {
+      expect(() => validateRedirectUrl("http://172.16.0.1/callback")).toThrow(
+        "private/internal address",
+      );
+      expect(() => validateRedirectUrl("http://172.31.255.255/")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should allow non-private 172.x.x.x", () => {
+      // 172.15.x.x and 172.32.x.x are public
+      expect(() =>
+        validateRedirectUrl("http://172.15.0.1/callback"),
+      ).not.toThrow();
+      expect(() =>
+        validateRedirectUrl("http://172.32.0.1/callback"),
+      ).not.toThrow();
+    });
+
+    it("should block private 192.168.x.x range", () => {
+      expect(() => validateRedirectUrl("http://192.168.0.1/callback")).toThrow(
+        "private/internal address",
+      );
+      expect(() => validateRedirectUrl("http://192.168.255.255/")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should block link-local 169.254.x.x", () => {
+      expect(() => validateRedirectUrl("http://169.254.1.1/callback")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should block AWS/GCP metadata endpoint 169.254.169.254", () => {
+      expect(() =>
+        validateRedirectUrl("http://169.254.169.254/latest/meta-data/"),
+      ).toThrow("private/internal address");
+    });
+
+    it("should block IPv6 localhost [::1]", () => {
+      expect(() => validateRedirectUrl("http://[::1]/callback")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should block IPv6 link-local [fe80::]", () => {
+      expect(() => validateRedirectUrl("http://[fe80::1]/callback")).toThrow(
+        "private/internal address",
+      );
+    });
+
+    it("should allow private IPs with allowPrivateIPs option", () => {
+      expect(() =>
+        validateRedirectUrl("http://localhost/callback", {
+          allowPrivateIPs: true,
+        }),
+      ).not.toThrow();
+      expect(() =>
+        validateRedirectUrl("http://127.0.0.1/callback", {
+          allowPrivateIPs: true,
+        }),
+      ).not.toThrow();
+      expect(() =>
+        validateRedirectUrl("http://192.168.1.1/callback", {
+          allowPrivateIPs: true,
+        }),
+      ).not.toThrow();
+    });
+
+    it("should allow public IPs", () => {
+      expect(() =>
+        validateRedirectUrl("https://api.example.com/callback"),
+      ).not.toThrow();
+      expect(() =>
+        validateRedirectUrl("https://8.8.8.8/callback"),
+      ).not.toThrow();
+      expect(() =>
+        validateRedirectUrl("https://1.1.1.1/callback"),
+      ).not.toThrow();
+    });
+  });
+});
+
+describe("isPrivateUrl", () => {
+  it("should return true for localhost", () => {
+    expect(isPrivateUrl("http://localhost/")).toBe(true);
+  });
+
+  it("should return true for private IPs", () => {
+    expect(isPrivateUrl("http://127.0.0.1/")).toBe(true);
+    expect(isPrivateUrl("http://10.0.0.1/")).toBe(true);
+    expect(isPrivateUrl("http://192.168.1.1/")).toBe(true);
+    expect(isPrivateUrl("http://172.16.0.1/")).toBe(true);
+  });
+
+  it("should return true for metadata endpoints", () => {
+    expect(isPrivateUrl("http://169.254.169.254/")).toBe(true);
+  });
+
+  it("should return false for public IPs", () => {
+    expect(isPrivateUrl("https://example.com/")).toBe(false);
+    expect(isPrivateUrl("https://8.8.8.8/")).toBe(false);
+    expect(isPrivateUrl("https://api.github.com/")).toBe(false);
+  });
+
+  it("should return false for invalid URLs", () => {
+    expect(isPrivateUrl("not a url")).toBe(false);
+  });
 });

client/src/utils/urlValidation.ts

@@ -1,24 +1,92 @@
+/**
+ * Check if a hostname is a private/internal IP address
+ * Used to prevent SSRF attacks by blocking requests to internal networks
+ */
+function isPrivateHostname(hostname: string): boolean {
+  const normalizedHostname = hostname.toLowerCase();
+
+  // Private IP patterns
+  const privatePatterns = [
+    // Localhost variants
+    /^localhost$/,
+    /^localhost\./,
+
+    // IPv4 private ranges
+    /^127\./, // 127.0.0.0/8 - loopback
+    /^10\./, // 10.0.0.0/8 - private
+    /^172\.(1[6-9]|2[0-9]|3[01])\./, // 172.16.0.0/12 - private
+    /^192\.168\./, // 192.168.0.0/16 - private
+    /^169\.254\./, // 169.254.0.0/16 - link-local
+    /^0\./, // 0.0.0.0/8 - current network
+
+    // IPv6 private ranges (enclosed in brackets for URL hostname)
+    /^\[::1\]$/, // ::1 - loopback
+    /^\[::ffff:127\./, // IPv4-mapped loopback
+    /^\[fe80:/i, // fe80::/10 - link-local
+    /^\[fc/i, // fc00::/7 - unique local
+    /^\[fd/i, // fd00::/8 - unique local
+
+    // Cloud metadata endpoints (common SSRF targets)
+    /^169\.254\.169\.254$/, // AWS/GCP metadata
+    /^metadata\./, // metadata.google.internal
+  ];
+
+  return privatePatterns.some((pattern) => pattern.test(normalizedHostname));
+}
+
 /**
  * Validates that a URL is safe for redirection.
- * Only allows HTTP and HTTPS protocols to prevent XSS attacks.
+ * - Only allows HTTP and HTTPS protocols to prevent XSS attacks
+ * - Blocks private/internal IPs to prevent SSRF attacks
  *
  * @param url - The URL string to validate
- * @throws Error if the URL has an unsafe protocol
+ * @param options - Validation options
+ * @param options.allowPrivateIPs - If true, allows private IPs (default: false)
+ * @throws Error if the URL has an unsafe protocol or points to private networks
  */
-export function validateRedirectUrl(url: string | URL): void {
+export function validateRedirectUrl(
+  url: string | URL,
+  options: { allowPrivateIPs?: boolean } = {},
+): void {
   try {
     const parsedUrl = new URL(url);
+
+    // Check protocol
     if (parsedUrl.protocol !== "http:" && parsedUrl.protocol !== "https:") {
       throw new Error("Authorization URL must be HTTP or HTTPS");
     }
+
+    // Check for private/internal IPs (SSRF protection)
+    if (!options.allowPrivateIPs && isPrivateHostname(parsedUrl.hostname)) {
+      throw new Error(
+        `Authorization URL cannot point to private/internal address: ${parsedUrl.hostname}`,
+      );
+    }
   } catch (error) {
     if (
       error instanceof Error &&
-      error.message === "Authorization URL must be HTTP or HTTPS"
+      (error.message.startsWith("Authorization URL") ||
+        error.message.startsWith("Authorization URL cannot"))
     ) {
       throw error;
     }
     // If URL parsing fails, it's also invalid
     throw new Error(`Invalid URL: ${url}`);
   }
 }
+
+/**
+ * Check if a URL points to a private/internal network
+ * Useful for warning users without blocking the request
+ *
+ * @param url - The URL to check
+ * @returns true if the URL points to a private network
+ */
+export function isPrivateUrl(url: string | URL): boolean {
+  try {
+    const parsedUrl = new URL(url);
+    return isPrivateHostname(parsedUrl.hostname);
+  } catch {
+    return false;
+  }
+}