Vulnerabilities

snappy-java is a Java port of the snappy, a fast C++ compresser/decompresser developed by Google. The SnappyInputStream was found to be vulnerable to Denial of Service (DoS) attacks when decompressing data with a too large chunk size. Due to missing upper bound check on chunk length, an unrecoverable fatal error can occur. All versions of snappy-java including the latest released version 1.1.10.3 are vulnerable to this issue. A fix has been introduced in commit `9f8c3cf74` which will be included in the 1.1.10.4 release. Users are advised to upgrade. Users unable to upgrade should only accept compressed data from trusted sources.

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.