I scanned my server with nikto and it shows me that its vulnerable to padding oracle vulnerability

+ OSVDB-68127: Server is vulnerable to http://www.microsoft.com/technet/security/bulletin/MS10-070.asp allowing a cryptographic padding oracle.

The page linked in the message has moved to https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/MS10-070

So I tried to exploit it with padbuster to see if nikto results are correct and it shows me this error

| PadBuster - v0.3.3                        |
| Brian Holyfield - Gotham Digital Science  |
| labs@gdssecurity.com                      |

ERROR: Encrypted Bytes must be evenly divisible by Block Size (16)
       Encrypted sample length is 124. Double check the Encoding and Block

However according to Acunetix's article I'm pretty sure my server is vulnerable because I did all the tests that in the article and it shows me exactly same results.

I did some search on the internet and some people saying the block size shouldn't be longer than 16, and if it's over 16 blocks then its not vulnerable. Mine are 124 and nikto and acunetix keep showing me it's vulnerable so now I'm really confused.

  • 1
    What are your inputs exactly? Padbuster takes 3 required arguments. I assume the third argument (blocksize) is 16 since that's what the error says. And I assume that the encrypted sample you provided is 124 in length. 124/16 = 7.75. It looks like you're missing 4 bytes in your encrypted sample. – Daisetsu Nov 4 '18 at 5:05
  • @Daisetsu Padbuster (website)/webresource.axd=* encrypted sample* encrypted sample once again and then block size -encoding=3 plaintext "|||~web.config" thats exactly my input. how can i find my server block size? sorry im just a newbie. and is it correct that if the encrypted sample longer than 16 blocks its not vulnerable? Thanks alot. – Waleed Nov 4 '18 at 6:03
  • Hmm, from what you've shown it appears you're running it right. Still I have to assume your encrypted sample must be missing something. Here's another tutorial of padbuster with actual command examples securitylearn.net/2011/08/19/padding-oracle-attack-explained does that help? – Daisetsu Nov 4 '18 at 6:28
  • @Daisetsu Nope, the problem is not with the exploit the problem now that i dont really know if my server is vulnerable or not anyway thanks alot mate. – Waleed Nov 4 '18 at 9:36
  • 1
    You've misread some things. Your block size is 16, and this is fine. 124 is the message size, not the block size. Beyond this, it's likely that nikto is right and you aren't using padbuster correctly, but I don't know nikto or padbuster so I can't help with that. You should edit your question to explain exactly how you're using padbuster. Why don't you upgrade your server, anyway? This is an 8-year old vulnerability! – Gilles Nov 4 '18 at 10:07

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