snappy-java through 1.1.10.8 contains a buffer overflow vulnerability in Snappy.compress(ByteBuffer, ByteBuffer) that writes past the end of the destination buffer. Attackers can supply incompressible data that exceeds the destination buffer's remaining capacity, corrupting off-heap memory and causing JVM termination.

Impact Snappy.uncompressCharArray, uncompressShortArray, uncompressIntArray, uncompressLongArray, uncompressFloatArray and uncompressDoubleArray sized the result array by dividing the declared uncompressed byte length by the element size, but native code wrote the full byte length. If the declared length is not a multiple of the element size, up to 7 bytes are written past the end of the Java array, corrupting the heap.

Patches Fixed in 1.1.10.9 (#739). These methods now reject uncompressed lengths that are not a multiple of the element size with SnappyIOException.

Workarounds Check that Snappy.uncompressedLength(input) is a multiple of the element size before calling these methods.

snappy-java through 1.1.10.8 contains an out-of-bounds write vulnerability in Snappy.uncompress(ByteBuffer, ByteBuffer) because destination buffer capacity is never validated against decompressed size. Attackers can supply valid compressed data that decompresses larger than the destination buffer, causing writes past buffer boundaries and JVM termination.