https://www.exploit-db.com/exploits/20218
http://www.cnnvd.org.cn/web/xxk/ldxqById.tag?CNNVD=CNNVD-200011-062

YaBB.pl是一个基于Web的公告牌脚本程序。YaBB.pl它将公告牌中的文章存放在编号的文本文件中。编号的文件名是在调用YaBB.pl时通过变量num=来指定的。在检索该文件之前，YaBB在后面添加一个后缀.txt。由于YaBB中的输入合法性检查错误，在中可以指定相对路径。这包括../类型的路径。此外，可以不是数字格式，而且.txt后缀可以通过在后面添加%00来避免。通过在单个请求中使用上述的这些漏洞，恶意用户可以察看Web服务器可以存取的任何文件。

source: http://www.securityfocus.com/bid/1668/info

YaBB.pl, a web-based bulletin board script, stores board postings in numbered text files. The numbered file name is specified in the call to YaBB.pl in the variable num=<file>. Before retrieving the file, YaBB will append a .txt extension to <file>.

Due to input validation problems in YaBB, relative paths can be specified in <file>. This includes ../ style paths.

Additionally, <file> does not need to be numerical, and the .txt extension can be avoided by appending %00 to <file>.

By exploiting these problems in a single request, a malicious user can view any file that the webserver has access to.

http://www.my_target.com/cgi-bin/YaBB.pl?board=news&action=display&num=../../../../../../../../etc/passwd%00

来源:BID
名称:1668
链接:http://www.securityfocus.com/bid/1668
来源:XF
名称:yabb-file-access
链接:http://xforce.iss.net/static/5254.php
来源:BUGTRAQ
名称:20000909YaBB1.9.2000Vulnerabilitie
链接:http://archives.neohapsis.com/archives/bugtraq/2000-09/0072.html
来源：NSFOCUS
名称：837
链接：http://www.nsfocus.net/vulndb/837