snappy-java unchecked chunk length DoS
org.xerial.snappy:snappy-java
(,1.1.10.1)
snappy-java is a fast compressor/decompressor for Java. Due to use of an unchecked chunk length, an unrecoverable fatal error can occur in versions prior to 1.1.10.1.
The code in the function hasNextChunk in the fileSnappyInputStream.java checks if a given stream has more chunks to read. It does that by attempting to read 4 bytes. If it wasn't possible to read the 4 bytes, the function returns false. Otherwise, if 4 bytes were available, the code treats them as the length of the next chunk.
In the case that the compressed variable is null, a byte array is allocated with the size given by the input data. Since the code doesn't test the legality of the chunkSize variable, it is possible to pass a negative number (such as 0xFFFFFFFF which is -1), which will cause the code to raise a java.lang.NegativeArraySizeException exception. A worse case would happen when passing a huge positive value (such as 0x7FFFFFFF), which would raise the fatal java.lang.OutOfMemoryError error.
Version 1.1.10.1 contains a patch for this issue.
package org.example;
import org.xerial.snappy.SnappyInputStream;
import java.io.*;
public class Main {
public static void main(String[] args) throws IOException {
byte[] data = {-126, 'S', 'N', 'A', 'P', 'P', 'Y', 0, 0, 0, 0, 0, 0, 0, 0, 0,(byte) 0x7f, (byte) 0xff, (byte) 0xff, (byte) 0xff};
SnappyInputStream in = new SnappyInputStream(new ByteArrayInputStream(data));
byte[] out = new byte[50];
try {
in.read(out);
}
catch (Exception ignored) {
}
}
}
No mitigations are supplied for this issue
https://github.com/xerial/snappy-java/commit/3bf67857fcf70d9eea56eed4af7c925671e8eaea
https://github.com/xerial/snappy-java/security/advisories/GHSA-qcwq-55hx-v3vh