snappy-java <1.1.10.1: Unchecked int overflow in compress() -> crash
CVE-2023-34454 Published on June 15, 2023
snappy-java's Integer Overflow vulnerability in compress leads to DoS
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 an unrecoverable fatal error.
The function `compress(char[] input)` in the file `Snappy.java` receives an array of characters and compresses it. It does so by multiplying the length by 2 and passing it to the rawCompress` function.
Since the length is not tested, the multiplication by two can cause an integer overflow and become negative. The rawCompress function then uses the received length and passes it to the natively compiled maxCompressedLength function, using the returned value to allocate a byte array.
Since the maxCompressedLength function treats the length as an unsigned integer, it doesnt care that it is negative, and it returns a valid value, which is casted to a signed integer by the Java engine. If the result is negative, a `java.lang.NegativeArraySizeException` exception will be raised while trying to allocate the array `buf`. On the other side, if the result is positive, the `buf` array will successfully be allocated, but its size might be too small to use for the compression, causing a fatal Access Violation error.
The same issue exists also when using the `compress` functions that receive double, float, int, long and short, each using a different multiplier that may cause the same issue. The issue most likely wont occur when using a byte array, since creating a byte array of size 0x80000000 (or any other negative value) is impossible in the first place.
Version 1.1.10.1 contains a patch for this issue.
Vulnerability Analysis
CVE-2023-34454 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. Public availability of a proof of concept (POC) exploit exists for CVE-2023-34454. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Integer Overflow or Wraparound
The software 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. An integer overflow or wraparound occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may wrap to become a very small or negative number. While this may be intended behavior in circumstances that rely on wrapping, it can have security consequences if the wrap is unexpected. This is especially the case if the integer overflow can be triggered using user-supplied inputs. This becomes security-critical when the result is used to control looping, make a security decision, or determine the offset or size in behaviors such as memory allocation, copying, concatenation, etc.
Products Associated with CVE-2023-34454
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Affected Versions
xerial snappy-java Version < 1.1.10.1 is affected by CVE-2023-34454Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.