Heap-Based Buffer Overflow

libcurl is vulnerable to heap-based buffer overflow. The vulnerability is due to not using upload buffer size for scratch buffer in Curl_smtp_escape_eob in lib/smtp.c. It is possible only when an attacker can get control over the data transmitted over SMTP using curl with certain settings (i.e., use of a nonstandard --limit-rate argument or CURLOPT_BUFFERSIZE value).,