Crypt::NaCl::Sodium versions through 2.002 for Perl has potential integer overflows.
bin2hex, encrypt, aes256gcm_encrypt_afternm and seal functions do not check that output size will be less than SIZE_MAX, which could lead to integer wraparound causing an undersized output buffer.
Encountering this issue is unlikely as the message length would need to be very large.
For bin2hex() the bin_len would have to be > SIZE_MAX / 2 For encrypt() the msg_len would need to be > SIZE_MAX - 16U For aes256gcm_encrypt_afternm() the msg_len would need to be > SIZE_MAX - 16U For seal() the enc_len would need to be > SIZE_MAX - 64U
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 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
become a very small or negative number.
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 [REF-1482].
- 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