There’s a new Vulnerability occur, and the id is CVE-2021-23840. The description is as below:
"Calls to EVP_CipherUpdate, EVP_EncryptUpdate and EVP_DecryptUpdate may overflow the output length argument in some cases where the input length is close to the maximum permissable length for an integer on the platform. In such cases the return value from the function call will be 1 (indicating success), but the output length value will be negative. This could cause applications to behave incorrectly or crash. "
The function EVP_CipherUpdate could be found in sqlcipher’s source code.So could it be possible that “the input length is close to the maximum permissable length” and cause this vulnerability? Or, as a user of sqlcipher, what should I do to avoid this vulnerability?
Looking forward for your reply，and thanks for your time！
：）
Thank you for sharing this. We are in the process of preparing a new release of SQLCipher. We have reviewed the above-referenced CVE and wanted to provide some additional context into the usage within SQLCipher when compiled with OpenSSL.
In the Community edition of SQLCipher, the only operation that could eventually call the Encrypt/Decrypt functions would be the pager codec. That has an externally enforced maximum page length, so the greatest length buffer that could be used is less than 65536 and therefore less than MAX_INT.
For our Commercial edition library, the encrypt, decrypt, cipher functions (via Value Level Encryption (VLE) functions) do allow arbitrary length input blobs. However, they do not use the output length and thus would not be susceptible to issues in a release build.
For versions of the library which use OpenSSL, the next release will utilize OpenSSL 1.1.1j.