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.
Weakness
The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Snappy-java |
Xerial |
* |
1.1.10.1 (excluding) |
Potential Mitigations
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- If possible, choose a language or compiler that performs automatic bounds checking.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use libraries or frameworks that make it easier to handle numbers without unexpected consequences.
- Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++). [REF-106]
- Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
- Use unsigned integers where possible. This makes it easier to perform validation for integer overflows. When signed integers are required, ensure that the range check includes minimum values as well as maximum values.
- Understand the programming language’s underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, “not-a-number” calculations, and how the language handles numbers that are too large or too small for its underlying representation. [REF-7]
- Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.
References