CURLcode Curl_auth_create_login_message(struct Curl_easy *data,
                                        const char *valuep, char **outptr,
                                        size_t *outlen)
{
  size_t vlen = strlen(valuep);

  if(!vlen) {
    /* Calculate an empty reply */
    *outptr = strdup("=");
    if(*outptr) {
      *outlen = (size_t) 1;
      return CURLE_OK;
    }

    *outlen = 0;
    return CURLE_OUT_OF_MEMORY;
  }

  /* Base64 encode the value */
  return Curl_base64_encode(data, valuep, vlen, outptr, outlen);
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.