CVE-2022-1713 (Java, published 2022-05-16T15:15Z)
Description: value: SSRF on /proxy in GitHub repository jgraph/drawio prior to 18.0.4. An attacker can make a request as the server and read its contents. This can lead to a leak of sensitive information.
Severity: MEDIUM (CVSS v3 base score: 7.5)
Weakness: CWE-918 \u2014 Server-Side Request Forgery (SSRF)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Repository: https://github.com/jgraph/drawio
Files changed:
src/main/java/com/mxgraph/online/ProxyServlet.java
Commit message: 18.0.3 release


Vulnerable code:
				String host = parsedUrl.getHost().toLowerCase();
						&& !host.endsWith(".internal")
						&& !host.endsWith(".local")
						&& !host.contains("localhost")
						&& !host.startsWith("0.") // 0.0.0.0/8
						&& !host.startsWith("10.") // 10.0.0.0/8
						&& !host.startsWith("127.") // 127.0.0.0/8
						&& !host.startsWith("169.254.") // 169.254.0.0/16
						&& !host.startsWith("172.16.") // 172.16.0.0/12
						&& !host.startsWith("172.17.") // 172.16.0.0/12
						&& !host.startsWith("172.18.") // 172.16.0.0/12
						&& !host.startsWith("172.19.") // 172.16.0.0/12
						&& !host.startsWith("172.20.") // 172.16.0.0/12
						&& !host.startsWith("172.21.") // 172.16.0.0/12
						&& !host.startsWith("172.22.") // 172.16.0.0/12
						&& !host.startsWith("172.23.") // 172.16.0.0/12
						&& !host.startsWith("172.24.") // 172.16.0.0/12
						&& !host.startsWith("172.25.") // 172.16.0.0/12
						&& !host.startsWith("172.26.") // 172.16.0.0/12
						&& !host.startsWith("172.27.") // 172.16.0.0/12
						&& !host.startsWith("172.28.") // 172.16.0.0/12
						&& !host.startsWith("172.29.") // 172.16.0.0/12
						&& !host.startsWith("172.30.") // 172.16.0.0/12
						&& !host.startsWith("172.31.") // 172.16.0.0/12
						&& !host.startsWith("192.0.0.") // 192.0.0.0/24
						&& !host.startsWith("192.168.") // 192.168.0.0/16
						&& !host.startsWith("198.18.") // 198.18.0.0/15
						&& !host.startsWith("198.19.") // 198.18.0.0/15

Fixed code:
import java.net.InetAddress;
				String host = parsedUrl.getHost();
				InetAddress address = InetAddress.getByName(host);
				String hostAddress = address.getHostAddress();
				host = host.toLowerCase();
						&& !address.isAnyLocalAddress()
						&& !address.isLoopbackAddress()
						&& !host.endsWith(".internal") // Redundant
						&& !host.endsWith(".local") // Redundant
						&& !host.contains("localhost") // Redundant
						&& !hostAddress.startsWith("0.") // 0.0.0.0/8 
						&& !hostAddress.startsWith("10.") // 10.0.0.0/8
						&& !hostAddress.startsWith("127.") // 127.0.0.0/8
						&& !hostAddress.startsWith("169.254.") // 169.254.0.0/16
						&& !hostAddress.startsWith("172.16.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.17.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.18.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.19.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.20.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.21.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.22.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.23.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.24.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.25.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.26.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.27.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.28.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.29.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.30.") // 172.16.0.0/12
						&& !hostAddress.startsWith("172.31.") // 172.16.0.0/12
						&& !hostAddress.startsWith("192.0.0.") // 192.0.0.0/24
						&& !hostAddress.startsWith("192.168.") // 192.168.0.0/16
						&& !hostAddress.startsWith("198.18.") // 198.18.0.0/15
						&& !hostAddress.startsWith("198.19.") // 198.18.0.0/15
			catch (UnknownHostException e)
			{
				return false;
			}