title: snappy-java's Integer Overflow vulnerability in shuffle leads to DoS
description: snappy-java is a fast compressor/decompressor for Java. Due to unchecked multiplications, an integer overflow may occur in versions prior to 1.1.10.1, causing a fatal error.
The function `shuffle(int[] input)` in the file `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. 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.
Version 1.1.10.1 contains a patch for this vulnerability.
problem types: CWE-190: Integer Overflow or Wraparound
affected:
{
vendor: xerial
product: snappy-java
versions:
version: < 1.1.10.1, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 5.9
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]