47、数据库安全攻防全解析

数据库安全攻防全解析

1. 攻击 Cold Fusion Web 应用时的 SQL 注入问题

在通过 Web 应用对 Microsoft SQL Server 进行 SQL 注入时,使用 Cold Fusion 编写的应用会自动去除单引号字符,这使得在 SQL 查询中输入字符串变得困难。不过,我们可以使用 chr() 函数来解决这个问题,该函数能将数字转换为对应的 ASCII 字符。

2. Microsoft SQL Server 的默认账户与配置

2.1 默认账户与密码问题

在管理良好的数据库中,默认用户账户和密码通常不是问题。但当数据库被集成到桌面应用(如 MSDE,它实际上是 MS SQL Server 的一个版本),或者由未经培训的人员部署,又或者暴露在新的、更具敌意的环境中时,这些默认设置往往会被忽视。例如,2002 年 5 月的 SQL Server 蠕虫(也称为 Spida.a.worm)就利用了 Microsoft SQL Server 7 上许多无密码的默认账户。即使到现在,查看防火墙记录仍能发现它在网络中扫描新目标。

一些常见的数据库默认用户名和密码如下:
- probe
- sa
- sql
- db
- dba
- 组织名称或机器名称

2.2 暴力破解工具

市面上有很多针对各种数据库 SQL 密码的暴力破解工具。如果 SQL 服务器的登录端口(通常是 TCP 1433)开放,那么很可能黑客已经对所有可能的登录进行了暴力字典攻击。需要注意的是,在某些配置下,Microsoft S

相关推荐

ASP.NET Core中间件管道深度解析与实战避坑指南

ASP.NET Core中间件管道是理解请求生命周期的核心机制,其本质是由委托链构成的‘洋葱模型’执行流。掌握其原理需厘清Func<HttpContext, Func<Task>, Task>签名逻辑、next调用时机及短路行为,技术价值在于实现可预测、可诊断、可干预的HTTP处理流程。典型应用场景包括自定义认证授权、日志追踪、异常熔断与响应压缩等,而真实生产问题如JWT状态丢失、CORS预检失败、HTTPS重定向失效,往往根源于中间件注册顺序或上下文污染。本文聚焦C#泛型约束与协变逆变边界推导在中间件设计

diaojin6880的博客 395

AM驱动架构—优质Mini-LED显示技术解决方案

(VR)和增强现实(AR)设备:MiniLED背光驱动方案适用于虚拟现实和增强现实设备中的显示技术,通过高亮度和高对比度的显示效果,创造更逼真的虚拟体验此外,MiniLED背光还能够实现更快的响应速度,减少图像残影,使得用户的动作在虚拟环境中更加流畅自然。以其出色的性能和广泛的应用前景备受关注是实现MiniLED显示效果的重要环节。1)更高的亮度和对比度:尺寸更小,可以在同样面积的显示屏上配置更多的LED,并且通过独立控制每一个MiniLED,可以实现更高的亮度和更细致的对比度,使得显示画面更加鲜明清晰。

isweekDN的博客 2761

中介效应、调节效应与交互效应:从概念辨析到统计建模全指南

在社会科学与数据分析研究中,理解变量之间的因果关系与条件性影响是核心任务之一。回归分析作为最基础的统计工具,常被用于探索自变量对因变量的作用机制,而中介效应与调节效应则分别回答了“如何影响”与“何时影响不同”的深层问题。中介效应通过路径分析拆解因果链条,揭示内部的传导机制;调节效应则借助交互项识别影响的边界条件。Bootstrap法已成为检验间接效应的主流手段,而简单斜率分析则让调节作用的模式更加直观。无论是用户研究、医学统计还是产品数据分析,掌握这些模型都能帮助研究者构建更具解释力的实证框架。本文基于大量

weixin_29051149的博客 330

大疆机场及无人机上云(航线规划、指令飞行...)

最近基于大疆上云api进行二次开发,后面将按照开发步骤对其进行说明!

资深三维GIS开发 5569

Arco Design Pro PC端商家后台框架 | Axure高保真原型库

摘要:本Axure原型设计方案基于字节跳动ArcoDesignPro规范,提供企业级后台快速搭建方案。包含动态表格、表单验证等核心组件,采用中继器驱动设计,支持响应式布局。方案覆盖80%后台常用交互,可节省60%原型制作时间,配套完整设计文档和组件库,实现原型到开发的高效衔接。特别适用于电商、SaaS等后台系统开发,支持权限管理、数据分析等场景,显著提升团队协作效率。

招风的黑耳优快云 3970

YOLOv11 TensorRT极致加速:C++部署性能优化完全指南

购买即可解锁300+YOLO优化文章,并且还有海量深度学习复现项目,价格仅需两杯奶茶的钱,别人有的本专栏也有!

LXY_LOVE36的博客 114

在 SAP S/4HANA Cloud Public Edition 中掌控 ABAP 生命周期管理:One-Off、Multi-Off 与 Scalable Delivery 的落地方法论

本文系统梳理了SAP S/4HANA Cloud Public Edition中ABAP扩展开发的三种生命周期管理模式:One-Off适用于企业内部扩展,通过Import Collection在三系统间流转;Multi-Off面向少量客户交付,基于gCTS和Git实现不连接系统间的传输;Scalable Delivery则将扩展产品化为add-on,支持规模化分发。文章结合RAP、OData等实际开发场景,对比分析了各模式的特点与适用边界,为国内团队提供了符合Public Cloud要求的开发与交付实践建议

2007 年 ~ 2025 年,深耕 SAP 技术 18 年 1494

Modbus RTU/TCP协议栈手写实现:主从站设计、功能码、CRC、异常响应

本文从协议栈架构、帧结构、功能码、CRC校验、异常响应、主从站设计等多个维度,完整阐述了Modbus RTU/TCP协议栈的手写实现方案。帧间隔机制是RTU的核心,T3.5超时检测决定了帧边界识别CRC16查表法以512字节ROM换取8倍性能提升,适合嵌入式功能码路由表实现可扩展的代码架构,便于新增功能异常响应机制保障协议健壮性,每个错误都有明确反馈Modbus TCP在RTU基础上增加MBAP头,实现以太网扩展多核RTOS环境下的并发访问与线程安全RS-485总线的电气隔离与浪涌保护。

从事移动开发八年,csdn博客专家,阿里云特邀专家,华为云云享专家,高级网络信息安全工程师,大数据工程师(高级),python技术开发(高级),HarmonyOS 应用开发者高级认证,现在某学校任教。 1万+

基于SVD矩阵分解的用户购物篮预测分析实战

基于SVD矩阵分解的用户购物篮预测分析实战

360

汉书HE8,好用的汇编代码编写工具

汉书HE8,好用的汇编代码编写工具早期编写汇编代码所用功能强大

VC中sqlite的使用

在VC中对sqlite的使用,实现数据库大批数据的快速插入,读取数据库中的数据在ListCtrl中显示

深度学习工具包 DeepLearningToolbox

深度学习工具包Deprecation notice.-----This toolbox is outdated and no longer maintained.There are much better tools available for deep learning than this toolbox, e.g. [Theano](http://deeplearning.net/software/theano/), [torch](http://torch.ch/) or [tensorflow](http://www.tensorflow.org/)I would suggest you use one of the tools mentioned above rather than use this toolbox.Best, Rasmus.DeepLearnToolbox================A Matlab toolbox for Deep Learning.Deep Learning is a new subfield of machine learning that focuses on learning deep hierarchical models of data.It is inspired by the human brain's apparent deep (layered, hierarchical) architecture.A good overview of the theory of Deep Learning theory is[Learning Deep Architectures for AI](http://www.iro.umontreal.ca/~bengioy/papers/ftml_book.pdf)For a more informal introduction, see the following videos by Geoffrey Hinton and Andrew Ng.* [The Next Generation of Neural Networks](http://www.youtube.com/watch?v=AyzOUbkUf3M) (Hinton, 2007)* [Recent Developments in Deep Learning](http://www.youtube.com/watch?v=VdIURAu1-aU) (Hinton, 2010)* [Unsupervised Feature Learning and Deep Learning](http://www.youtube.com/watch?v=ZmNOAtZIgIk) (Ng, 2011)If you use this toolbox in your research please cite [Prediction as a candidate for learning deep hierarchical models of data](http://www2.imm.dtu.dk/pubdb/views/publication_details.php?id=6284)```@MASTERSTHESIS\{IMM2012-06284, author = "R. B. Palm", title = "Prediction as a candidate for learning deep hierarchical models of data", year = "2012",}```Contact: rasmusbergpalm at gmail dot comDirectories included in the toolbox-----------------------------------`NN/` - A library for Feedforward Backpropagation Neural Networks`CNN/` - A library for Convolutional Neural Networks`DBN/` - A library for Deep Belief Networks`SAE/` - A library for Stacked Auto-Encoders`CAE/` - A library for Convolutional Auto-Encoders`util/` - Utility functions used by the libraries`data/` - Data used by the examples`tests/` - unit tests to verify toolbox is workingFor references on each library check REFS.mdSetup-----1. Download.2. addpath(genpath('DeepLearnToolbox'));Example: Deep Belief Network---------------------```matlabfunction test_example_DBNload mnist_uint8;train_x = double(train_x) / 255;test_x = double(test_x) / 255;train_y = double(train_y);test_y = double(test_y);%% ex1 train a 100 hidden unit RBM and visualize its weightsrand('state',0)dbn.sizes = [100];opts.numepochs = 1;opts.batchsize = 100;opts.momentum = 0;opts.alpha = 1;dbn = dbnsetup(dbn, train_x, opts);dbn = dbntrain(dbn, train_x, opts);figure; visualize(dbn.rbm{1}.W'); % Visualize the RBM weights%% ex2 train a 100-100 hidden unit DBN and use its weights to initialize a NNrand('state',0)%train dbndbn.sizes = [100 100];opts.numepochs = 1;opts.batchsize = 100;opts.momentum = 0;opts.alpha = 1;dbn = dbnsetup(dbn, train_x, opts);dbn = dbntrain(dbn, train_x, opts);%unfold dbn to nnnn = dbnunfoldtonn(dbn, 10);nn.activation_function = 'sigm';%train nnopts.numepochs = 1;opts.batchsize = 100;nn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.10, 'Too big error');```Example: Stacked Auto-Encoders---------------------```matlabfunction test_example_SAEload mnist_uint8;train_x = double(train_x)/255;test_x = double(test_x)/255;train_y = double(train_y);test_y = double(test_y);%% ex1 train a 100 hidden unit SDAE and use it to initialize a FFNN% Setup and train a stacked denoising autoencoder (SDAE)rand('state',0)sae = saesetup([784 100]);sae.ae{1}.activation_function = 'sigm';sae.ae{1}.learningRate = 1;sae.ae{1}.inputZeroMaskedFraction = 0.5;opts.numepochs = 1;opts.batchsize = 100;sae = saetrain(sae, train_x, opts);visualize(sae.ae{1}.W{1}(:,2:end)')% Use the SDAE to initialize a FFNNnn = nnsetup([784 100 10]);nn.activation_function = 'sigm';nn.learningRate = 1;nn.W{1} = sae.ae{1}.W{1};% Train the FFNNopts.numepochs = 1;opts.batchsize = 100;nn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.16, 'Too big error');```Example: Convolutional Neural Nets---------------------```matlabfunction test_example_CNNload mnist_uint8;train_x = double(reshape(train_x',28,28,60000))/255;test_x = double(reshape(test_x',28,28,10000))/255;train_y = double(train_y');test_y = double(test_y');%% ex1 Train a 6c-2s-12c-2s Convolutional neural network %will run 1 epoch in about 200 second and get around 11% error. %With 100 epochs you'll get around 1.2% errorrand('state',0)cnn.layers = { struct('type', 'i') %input layer struct('type', 'c', 'outputmaps', 6, 'kernelsize', 5) %convolution layer struct('type', 's', 'scale', 2) %sub sampling layer struct('type', 'c', 'outputmaps', 12, 'kernelsize', 5) %convolution layer struct('type', 's', 'scale', 2) %subsampling layer};cnn = cnnsetup(cnn, train_x, train_y);opts.alpha = 1;opts.batchsize = 50;opts.numepochs = 1;cnn = cnntrain(cnn, train_x, train_y, opts);[er, bad] = cnntest(cnn, test_x, test_y);%plot mean squared errorfigure; plot(cnn.rL);assert(er<0.12, 'Too big error');```Example: Neural Networks---------------------```matlabfunction test_example_NNload mnist_uint8;train_x = double(train_x) / 255;test_x = double(test_x) / 255;train_y = double(train_y);test_y = double(test_y);% normalize[train_x, mu, sigma] = zscore(train_x);test_x = normalize(test_x, mu, sigma);%% ex1 vanilla neural netrand('state',0)nn = nnsetup([784 100 10]);opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samples[nn, L] = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.08, 'Too big error');%% ex2 neural net with L2 weight decayrand('state',0)nn = nnsetup([784 100 10]);nn.weightPenaltyL2 = 1e-4; % L2 weight decayopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex3 neural net with dropoutrand('state',0)nn = nnsetup([784 100 10]);nn.dropoutFraction = 0.5; % Dropout fraction opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex4 neural net with sigmoid activation functionrand('state',0)nn = nnsetup([784 100 10]);nn.activation_function = 'sigm'; % Sigmoid activation functionnn.learningRate = 1; % Sigm require a lower learning rateopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex5 plotting functionalityrand('state',0)nn = nnsetup([784 20 10]);opts.numepochs = 5; % Number of full sweeps through datann.output = 'softmax'; % use softmax outputopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex6 neural net with sigmoid activation and plotting of validation and training error% split training data into training and validation datavx = train_x(1:10000,:);tx = train_x(10001:end,:);vy = train_y(1:10000,:);ty = train_y(10001:end,:);rand('state',0)nn = nnsetup([784 20 10]); nn.output = 'softmax'; % use softmax outputopts.numepochs = 5; % Number of full sweeps through dataopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, tx, ty, opts, vx, vy); % nntrain takes validation set as last two arguments (optionally)[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');```[![Bitdeli Badge](https://d2weczhvl823v0.cloudfront.net/rasmusbergpalm/deeplearntoolbox/trend.png)](https://bitdeli.com/free "Bitdeli Badge")

上一篇: 6、量子计算在人文研究中的应用与QHAna工具解析
下一篇: 54、Python 杂项库模块与 C 扩展开发全解析
leaf8
博客等级 码龄24年 45粉丝 1153原创
评论
成就一亿技术人!
拼手气红包6.0元
还能输入1000个字符  | 博主筛选后可见
 
 条评论被折叠 查看
添加红包

请填写红包祝福语或标题

个

红包个数最小为10个

元

红包金额最低5元

当前余额3.43元 前往充值 >
需支付:10.00元
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付元
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值