Tag Archives: Cisco

What’s wrong with patch-based Vulnerability Management checks?

What’s wrong with patch-based Vulnerability Management checks? My last post about Guinea Pigs and Vulnerability Management products may seem unconvincing without some examples. So, let’s review one. It’s a common problem that exists among nearly all VM vendors, I will demonstrate it on Tenable Nessus.

If you perform vulnerability scans, you most likely seen these pretty huge checks in your scan results like “KB4462917: Winsdows 10 Version 1607 and Windows Server 2016 October 2018 Security Update“. This particular Nessus plugin detects 23 CVEs at once.

What's wrong with patch-centric Vulnerability Management?

And, as you can see, it has formalized “Risk Information” data in the right column. There is only one CVSS score and vector, one CPE, one exploitability flag, one criticality level. Probably because of architectural limitations of the scanner. So, two very simple questions:

  • for which CVE (of these 23) is this formalized Risk Information block?
  • for which CVE (of these 23) exploit is available?

Ok, maybe they show CVSS for the most critical (by their logic) CVE. Maybe they somehow combine this parameter from data for different CVEs. But in most cases this will be inaccurate. Risk information data for every of these 23 vulnerabilities should be presented independently.

As you can see on the screenshot, one of these vulnerabilities is RCE the other is Information Disclosure. Vulnerability Management solution tells us that there is an exploit. Is this exploit for RCE or DoS? You should agree, that it can be crucial for vulnerability prioritization. And more than this, in the example there are 7 different RCEs in Internet Explorer, MSXML parser, Windows Hyper-V, etc. All this mean different attack scenarios. How is it possible to show it Vulnerability Scanner like one entity with one CVSS and exploitability flag? What can the user get from this? How to search in all this?

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CyberThursday: Asset Inventory, IT-transformation in Cisco, Pentest vs. RedTeam

CyberThursday: Asset Inventory, IT-transformation in Cisco, Pentest vs. RedTeam. Two weeks ago I was speaking at a very interesting information security event – CyberThursday. This is a meeting of a closed Information Security practitioners group. The group is about 70 people, mainly from the financial organizations, telecoms and security vendors.

CyberThursday 2018 Asset Inventory

These meetings have a rather unique atmosphere. Almost everyone knows each other. The event has no permanent place. It constantly moves between the offices of large Russian companies. The hoster, usually a CISO, can bring his IT and InfoSec colleagues. For others, only “bring a friend” format is available. This helps keep the event focussed and very informal. Participants propose and approve the topics by voting in the chat group. There is no place for marketing, all topics are practical and relevant.

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Asset Inventory for Internal Network: problems with Active Scanning and advantages of Splunk

Asset Inventory for Internal Network: problems with Active Scanning and advantages of Splunk. In the previous post, I was writing about Asset Inventory and Vulnerability Scanning on the Network Perimeter. Now it’s time to write about the Internal Network.

Typical IT-infrastructure of a large organization

I see a typical IT-infrastructure of a large organization as monstrous favela, like Kowloon Walled City in Hong Kong. At the beginning it was probably wisely designed, but for years it  was highly effected by spontaneous development processes in various projects as well as multiple acquisitions. And now very few people in the organization really understand how it all works and who owns each peace.

There is a common belief that we can use Active Network Scanning for Asset Inventory in the organization. Currently, I’m not a big fan of this approach, and I will try to explain here the disadvantages of this method and mention some alternatives.

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Vulnerability Databases: Classification and Registry

Vulnerability Databases: Classification and Registry. What publicly available Vulnerability Databases do we have? Well, I can only say that there are a lot of them and they are pretty different. Here I make an attempt to classify them.

It’s quite an ungrateful task. No matter how hard you try, the final result will be rather inaccurate and incomplete. I am sure someone will be complaining. But this is how I see it. 😉 If you want to add or change something feel free to make a comment bellow or email me@avleonov.com.

The main classifier, which I came up with:

  • There are individual vulnerability databases in which one identifier means one vulnerability. They try to cover all existing vulnerabilities.
  • And others are security bulletins. They cover vulnerabilities in a particular product or products. And they usually based on on patches. One patch may cover multiple vulnerabilities.

I made this diagram with some Vulnerability Databases. Note that I wanted to stay focused, so there are no exploit DBs, CERTs, lists of vulnerabilities detected by some researchers (CISCO Talos, PT Research, etc.), Media and Bug Bounty sites.

Vulnerability Databases classification

For these databases the descriptions of vulnerabilities are publicly available on the site (in html interface or downloadable data feed), or exist in a form of paid Vulnerability Intelligence service (for example, Flexera).

On one side there are databases of individual vulnerabilities, the most important is National Vulnerability Database. There are also Chinese, Japanese bases that can be derived from NVD or not.

On the other side we have security bulletins, for example RedHat Security Advisories.

And in the middle we have a Vulnerability Databases, for which it is not critical whether they have duplicated vulnerability IDs or not.

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What’s inside Vulners.com database and when were security objects updated last time

What’s inside Vulners.com database and when were security objects updated last time. As I already wrote earlier, the main advantage of Vulners.com, in my opinion, is openness. An open system allows you to look under the hood, make sure that everything works fine and ask developers uncomfortable questions why there were no updates for a long time for some types of security objects.

You can do this by using the https://vulners.com/api/v3/search/stats/ request, that I already mentioned in “Downloading entire Vulners.com database in 5 minutes

First of all, let’s look at the security objects. This will give us an understanding of Vulners.com basis.

Vulners objects

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Petya, M.E.Doc and the problem of trust

Petya, M.E.Doc and the problem of trust. I’ve already mentioned in “Petya the Great and why *they* don’t patch vulnerabilities“, that NotPetya ransomware seems trivial from Vulnerability Management point of view. It uses known Windows vulnerabilities, that were patched by Microsoft long time ago.

Despite of this, I was really interested in M.E.Doc (servers were confiscated by Ukrainian police and website is not operational) role in the initial phase of malware spreading. In my opinion, we have a pretty interesting example of an attack vector, that will be very hard to detect and mitigate. And moreover, it’s once again shows that protected perimeter won’t be a panacea anymore.

m.e.doc

M.E.Doc – My Electronic Document Circulation System. “m.e.doc” sounds like the word, that mean “honey” in Russian and Ukrainian. That’s why all these bees in promo materials.

M.E.Doc is an Document Circulation System very popular in Ukraine. It makes possible to send reports to the government authorities in electronic form. It can be used in any organization. I can even imagine situation when usage of this kind of software may be even mandatory. Now the researchers [Eset, Dr.Web] say that M.E.Doc servers sent updates with backdoors  to the customers.

This backdoor has abilities:

  • Data collection for accessing mail servers
  • Arbitrary commands execution in the infected system
  • Running any executables
  • Downloading arbitrary files to the infected computer
  • Uploading arbitrary files to a remote server
  • Identify the exact organization using EDRPOU number.

I don’t really care about technical details about this backdoor. For me it’s enough that malicious code was on official server of the vendor and was spread to legitimate customers. Boom!

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Vulners – Google for hacker. How the best vulnerability search engine works and how to use it

Vulners – Google for hacker. How the best vulnerability search engine works and how to use it. Original article was published in Xakep Magazine #06/2016 (in Russian)

vulners.com logo

The common task. Уou need to find all information about some vulnerability: how critical the bug is, whether there is a public exploit, which vendors already released patches, which vulnerability scanner can detect this bug in the system. Previously, you had to search it all manually in dozens of sources (CVEDetails, SecurityFocus, Rapid7 DB, Exploit-DB, CVEs from MITRE / NIST, vendor newsletters, etc.) and analyze the collected data. Today, this routine can be (and should be!) automated with specialized services. One of these services – Vulners.com, the coolest search engine for bugs. And what is the most important – it’s free and has an open API. Let’s see how it can be useful for us.

What is it?

Vulners is a very large constantly updating database of Information Security content. This site lets you search for vulnerabilities, exploits, patches, bug bounty programs the same way a web search engine lets you search for websites. Vulners aggregates and presents in convenient form seven major types of data:

  • Popular vulnerability databases, containing general descriptions of vulnerabilities and links. For example, well-known NVD CVEs of MITRE US agency and NIST Institute. In addition to this, Vulners supports vulnerability descriptions from various research centers and response teams: Vulnerability Lab, XSSed, CERT, ICS, Zero Day Initiative, Positive Technologies, ERPScan.
  • Vendor’s security bulletins. This bug-reports are published by software vendors and contain information about vulnerabilities in their own products. At current moment Vulners supports various Linux distributions (Red Hat, CentOS, Oracle Linux, Arch Linux, Debian, Ubuntu, SUSE), FreeBSD, network devices (F5 Networks, Cisco, Huawei, Palo Alto Networks), popular and critical software (OpenSSL, Samba, nginx, Mozilla, Opera), including CMS (WordPress, Drupal).
  • Exploits from Exploit-DB, Metasploit and 0day.today. Exploits are parsed and stored in full-text form and you can read the sources in a convenient text editor.
  • Nessus plugins for vulnerability detection. It makes easy to find out whether a particular vulnerability can be detected using this popular network scanner. Why is it important? Read in my article “When a free scanning service detects vulnerabilities better“.
  • Bug disclousers for bug bounty programs. At current moment Vulners supports HackerOne and Open Bug Bounty.
  • Potential vulnerabilities of mobile applications and CMS. It is possible in cooperation with the static application security testing (SAST) vendors Hackapp and InfoWatch APPERCUT.
  • Posts from hacking resources. Vulners collects Threatpost and rdot.org publications, which often cover vulnerability related topics.

All this information is handled, cataloged, structured and is always available for the search.

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