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关于图片上传安全的问题

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Jun 23, 2016 pm 02:19 PM

一般我只检查后缀名，
比如上传abc.jpg，最后放在/xxx/xxx.jpg

但是今天看见一篇文章
原理是一段代码制作成JPG图片，然后上传。
关于图片上传安全的问题这时就执行代码？

我百度了很久找到的都是10年前的资料，而且好像这个东西跟ASP相关的？
我想问这个PHP是否也有这个漏洞？
文件上传时只检查后缀是否安全？

回复讨论(解决方案)

php也一样，上传以后，最好先判断是否是真实的图片文件，然后弄个透明水印上去，相当于“破坏”原图

php也一样，上传以后，最好先判断是否是真实的图片文件，然后弄个透明水印上去，相当于“破坏”原图

如何判断
加水印暂时没有这个考虑

不安全...
一般我只检查后缀名，
比如上传abc.jpg，最后放在/xxx/xxx.jpg

但是今天看见一篇文章
原理是一段代码制作成JPG图片，然后上传。
关于图片上传安全的问题这时就执行代码？

我百度了很久找到的都是10年前的资料，而且好像这个东西跟ASP相关的？
我想问这个PHP是否也有这个漏洞？
文件上传时只检查后缀是否安全？

php也一样，上传以后，最好先判断是否是真实的图片文件，然后弄个透明水印上去，相当于“破坏”原图

如何判断
加水印暂时没有这个考虑

百度就有啊。。。

原来还有这样的问题啊。。长见识了！

不安全...

应该检查哪些项目？

百度就有啊。。。

getimagesize？

if (preg_match('/ die('提示！禁止提交。该图片含有禁止的代码'.str_replace('?', '\?', $m_err[0]).'。');
}

if (preg_match('/ die('提示！禁止提交。该图片含有禁止的代码'.str_replace('?', '\?', $m_err[0]).'。');
}

能不能给个简单的图片试一下，比如执行

1.你把所有存放图片的目录权限都设为“可读可写不可执行”，包括临时存放的目录也是
2.检查是否真实图片，jpg等要切尾，切尾就是了解图片格式，把图片尾段“额外”的字节扔掉，搜索一下能找到相关文章

基本做好这两点就相对安全了，尤其第一点相当重要

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