Explore the nature of vulnerabilities in this episode of ThreatWise TV.
It’s shaping up to be another big year for vulnerability disclosure. Already the number of Common Vulnerabilities and Exposures (CVEs) disclosed has crossed 18,000 and it’s on track to make this another record-breaking year.
With new CVEs being disclosed daily, it has become increasingly difficult for security teams to stay abreast of the latest risks, let alone quickly determine which ones apply to their network environment. From those, prioritizing which CVEs to patch first adds an additional wrinkle to the process.
If this wasn’t challenging enough, a curve ball that’s often lobbed at security teams are the “breaking news” vulnerabilities— vulnerabilities picked up by the security media, often with much fanfare. The stories surrounding these high-profile vulnerabilities generally carry an implied threat that the CVE in question will throw the doors wide open to attackers if not addressed immediately. What security team hasn’t had someone from the C-suite share an article they’ve read, asking “are we protected from this?”
On the surface, CVEs that appear severe enough to garner media attention do seem like a good place to start when addressing vulnerabilities in your environment. But vulnerabilities are complicated, and what a security researcher manages to do within a controlled environment doesn’t always translate into real-world attacks. In fact, most disclosed vulnerabilities never see active exploitation. And of those that do, not every vulnerability ends up becoming a tool in an attacker’s arsenal. Bad actors generally follow the path of least resistance when they compromise a network, relying on tested exploits long before trying something new and unproven.
This begs the question: how much overlap is there between the most talked about vulnerabilities and those that are widely used in attacks? Moreover, if media attention isn’t a reliable indicator, what else might predict if a vulnerability will be used in an attack?
To answer these questions, we used intelligence tools available from Cisco’s Kenna Security risk-based vulnerability management (RBVM) software. In particular, Kenna.VI+ consolidates a variety of vulnerability intelligence, where a CVE ID lookup can pull back a wealth of information. In addition to this, Kenna.VI+ includes an API that brings in an additional layer of external threat intelligence, enabling further analysis.
We started with a direct comparison of Successful Exploitations and Chatter Count from within Kenna.VI+. The former is a full count of confirmed exploits within the dataset, while the latter is a count of mentions in the news, social media, various forums, and the dark web.
Our first pass at the data included a comparison of the top 50 CVEs in both Successful Exploitations and Chatter Count. However, there were only two CVEs that overlapped. The data showed that many of the top exploited CVEs were old and predated the data in Chatter Count. We quickly decided that this wasn’t a fair comparison.
To get a better look at more relevant CVEs, we limited the dataset to a range of 10 years. Unfortunately, this did not do much to improve things—only three CVEs showed up in both lists.
A more effective approach was to look at CVEs that we know are actively being exploited. The Cybersecurity and Infrastructure Security Agency (CISA) happens to maintain such a list. The Known Exploited Vulnerabilities (KEV) catalog is considered an authoritative compilation of vulnerabilities identified as being actively exploited in the wild.
Running the KEV catalog though Kenna.VI+ resulted in six CVEs that appeared in the top 50 for both lists, with a single overlap in the top 10. This leads us to conclude that the vulnerabilities with the most discussion are not the same as those being actively exploited in the majority of cases.
CVE | Brief description | |
1 | CVE-2017-9841 | PHPUnit vulnerability (used to target popular CMSes) |
2 | CVE-2021-44228 | Log4j vulnerability |
3 | CVE-2019-0703 | Windows SMB information disclosure vulnerability |
4 | CVE-2014-0160 | Heartbleed vulnerability |
5 | CVE-2017-9805 | REST plugin in Apache Struts vulnerability |
6 | CVE-2017-11882 | Microsoft Office memory corruption vulnerability |
7 | CVE-2017-5638 | Apache Struts vulnerability (used in Equifax breach) |
8 | CVE-2012-1823 | 10-year-old PHP vulnerability |
9 | CVE-2017-0144 | EternalBlue vulnerability |
10 | CVE-2018-11776 | Apache Struts RCE vulnerability |
CVE | Brief description | |
1 | CVE-2021-26855 | Microsoft Exchange vulnerability (used in Hafnium attacks) |
2 | CVE-2021-40444 | Microsoft MSHTML RCE vulnerability |
3 | CVE-2021-26084 | Confluence Server and Data Center vulnerability |
4 | CVE-2021-27065 | Microsoft Exchange vulnerability (used in Hafnium attacks) |
5 | CVE-2021-34473 | Microsoft Exchange vulnerability (used in Hafnium attacks) |
6 | CVE-2021-26858 | Microsoft Exchange vulnerability (used in Hafnium attacks) |
7 | CVE-2021-44228 | Log4j vulnerability |
8 | CVE-2021-34527 | One of the PrintNightmare vulnerabilities |
9 | CVE-2021-41773 | Apache HTTP Server vulnerability |
10 | CVE-2021-31207 | One of the ProxyShell vulnerabilities |
Despite the lack of overlap, there are many well-known vulnerabilities at the top of both lists. Heartbleed and EternalBlue appear on the top 10 exploited list, while Hafnium, PrintNightmare, and ProxyShell make the top 10 most talked about CVEs.
The Log4j vulnerability is the only CVE that appears in both lists. This isn’t surprising considering the ubiquity of Log4j in modern software. It’s the second-most exploited vulnerability—far outpacing the CVEs directly below it. This, coupled with its appearance in the chatter list, puts it in a class of its own. In a brief period, it’s managed to outpace older CVEs that are arguably just as well known.
The CVE that recorded the most successful exploitations is a five-year-old vulnerability in PHPUnit. This is a popular unit-testing framework that’s used by many CMSes, such as Drupal, WordPress, MediaWiki, and Moodle.
Since many websites are built with these tools, this exploit can be a handy vector for gaining initial access to unpatched webservers. This also lines up with research we conducted last year, where this vulnerability was one of the most common Snort detections seen by Cisco Secure Firewall.
All four of the Microsoft Exchange Server vulnerabilities used in the Hafnium attacks appear in the most talked about list of CVEs. However, even when you add all four of these CVEs together, they still don’t come anywhere close to the counts seen in the top exploited CVEs.
If media attention is not a good predictor of use for exploitation, then what are the alternatives?
The Common Vulnerability Scoring System (CVSS) is a well-known framework for gauging the severity of vulnerabilities. We looked for CVEs from the KEV catalog that were ranked as “critical”—9.0 and above in the CVSSv3 specification. Examining the entire KEV catalog, 28% of the CVEs have a score of 9.0 or higher. Of the top 50 successfully exploited, 38% had such scores.
This is an improvement, but the CVSSv3 specification was released in 2015. Many CVEs in the KEV catalog predate this—19% of the entire catalog and 28% of the top 50—and have no score.
Using the previous CVSS specification does fill this gap—36% overall and 52% of the top 50 score 9.0 or higher. However, the older CVSS specification comes with its share of issues as well.
Another indicator worth exploring is remote control execution (RCE). A vulnerability with RCE grants an attacker the ability to access and control a vulnerable system from anywhere. It turns out that 45% of the CVEs in our dataset allow for RCE, and 66% of the top 50, making it the most worthwhile indicator analyzed.
Let’s summarize how we’ve honed our approach to determine if media attention and exploitation line up:
Data set | Exploitation and Chatter lists | Number of CVEs |
All CVEs | Appears in both top 50 | 2 |
Appears in both top 50 (last 10 years) | 3 | |
KEV Catalog | Appears in both top 50 | 6 |
Appears in both top 10 | 1 |
And here’s a summary of our look at other indicators:
KEV Catalog | Top 50 exploited | |
CVSSv3 (9.0+) | 28% | 38% |
CVSS (9.0+) | 36% | 52% |
Allows for RCE | 45% | 66% |
All of this analysis provides a clear answer to our original question—the most regularly exploited CVEs aren’t the most talked about. Additional work highlights that monitoring variables like RCE can help with prioritization.
For illustrative purposes we’ve only looked at a few indicators that could be used to prioritize CVEs. While some did better than others, we don’t recommend relying on a single variable in making decisions about vulnerability management. Creating an approach that folds in multiple indicators is a far better strategy when it comes to real-world application of this data. And while our findings here speak to the larger picture, every network is different.
Regardless of which list they appear on, be it Successful Exploitations or Chatter Count, it’s important to point out that all these vulnerabilities are serious. Just because Hafnium has more talk than Heartbleed doesn’t make it any less dangerous if you have assets that are vulnerable to it. The fact is that while CVEs with more talk didn’t make the top of the exploitation list, they still managed to rack up tens of thousands of successful exploitations.
It’s important to know how to prioritize security updates, fixing those that expose you to the most risk as soon as possible. From our perspective, here are some basic elements in the Cisco Secure portfolio that can help.
Kenna Security, a pioneer in risk-based vulnerability management, relies on threat intel and prioritization to keep security and IT teams focused on risks. Using data science, Kenna processes and analyzes 18+ threat and exploit intelligence feeds, and 12.7+ billion managed vulnerabilities to give you an accurate view of your company’s risk. With our risk scoring and remediation intelligence, you get the info you need to make truly data-driven remediation decisions.
To responsibly protect a network, it’s important to monitor all assets that connect to it and ensure they’re kept up to date. Duo Device Trust can check the patch level of devices for you before they’re granted access to connect to corporate applications or sensitive data. You can even block access and enable self-remediation for devices that are found to be non-compliant.
How about remote workers? By leveraging the Network Visibility Module in Cisco Secure Client as a telemetry source, Cisco Secure Cloud Analytics can capture endpoint-specific user and device context to supply visibility into remote worker endpoint status. This can bolster an organization’s security posture by providing visibility on remote employees that are running software versions with vulnerabilities that need patching.
Lastly, for some “lateral thinking” about vulnerability management, take a look at this short video of one of our Advisory CISOs, Wolfgang Goerlich. Especially if you’re a fan of the music of the 1920s…
We’d love to hear what you think. Ask a Question, Comment Below, and Stay Connected with Cisco Secure on social!
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There’s little rest for your hard-working smartphone. If you’re like many professionals today, you use it for work, play, and a mix of personal business in between. Now, what if something went wrong with that phone, like loss or theft? Worse yet, what if your smartphone got hacked? Let’s try and keep that from happening to you.
Globally, plenty of people pull double duty with their smartphones. In Spain, one survey found that 55% of people use the same phone for a mix of personal and and work activity. The same survey showed that up to half of people interviewed in Japan, Australia, and the U.S. do so as well, while nations like the UK and Germany trailed at 31% and 23% respectively.
Whether these figures trend on the low or high end, the security implications remain constant. A smartphone loaded with business and personal data makes for a desirable target. Hackers target smartphones because they’re often unprotected, which gives hackers an easy “in” to your personal information and to any corporate networks you may use. It’s like two hacks with one stone.
Put simply, as a working professional with a smartphone, you’re a high-value target.
As both a parent and a professional, I put together a few things you can do to protect your smartphone from hacks so that you can keep your personal and work life safe:
First up, the basics. Locking your phone with facial ID, a fingerprint, pattern or a pin is your most basic form of protection, particularly in the event of loss or theft. (Your options will vary depending on the device, operating system, and manufacturer.) Take it a step further for even more protection. Secure the accounts on your phone with strong passwords and use two-factor authentication on the apps that offer it, which doubles your line of defense.
Or, put another way, don’t hop onto public Wi-Fi networks without protection. A VPN masks your connection from hackers allowing you to connect privately when you are on unsecure public networks at airports, cafes, hotels, and the like. With a VPN connection, you’ll know that your sensitive data, documents, and activities you do are protected from snooping, which is definitely a great feeling given the amount of personal and professional business we manage with our smartphones.
Both Google Play and Apple’s App Store have measures in place to help prevent potentially dangerous apps from making it into their stores. Malicious apps are often found outside of the app stores, which can run in the background and compromise your personal data like passwords, credit card numbers, and more—practically everything that you keep on your phone. Further, when you are in the app stores, look closely at the descriptions and reviews for apps before you download them. Malicious apps and counterfeits can still find their way into stores, and here are a few ways you can keep those bad apps from getting onto your phone.
Backing up your phone is always a good idea for two reasons:
Both iPhones and Android phones have straightforward ways of backing up your phone regularly.
Worst case scenario—your phone is gone. Really gone. Either it’s hopelessly lost or got stolen. What now? Lock it remotely or even wipe its data entirely. While that last bit about wiping the phone seems like a drastic move, if you maintain regular backups as mentioned above, your data is secure in the cloud—ready for you to restore. In all, this means that hackers won’t be able to access you, or your company’s, sensitive information—which can keep you out of trouble and your professional business safe. Apple provides iOS users with a step-by-step guide for remotely wiping devices, and Google offers up a guide for Android users as well.
We all download apps, use them once, and then forget they are on our phone. Take a few moments to swipe through your screen and see which ones you’re truly done with and delete them along with their data. Some apps have an account associated with them that may store data off your phone as well. Take the extra step and delete those accounts so any off-phone data is deleted.
The reason for this is that every extra app is another app that needs updating or that may have a security issue associated with it. In a time of data breaches and vulnerabilities, deleting old apps is a smart move. As for the ones you keep, update them regularly and turn on auto-updates if that’s an option. Updates not only introduce new features to apps, but they also often address security issues too.
With so much of your life on your phone, getting security software installed on it can protect you and the things you keep on your phone. Whether you’re an Android owner or iOS owner, mobile security software can keep your data, your shopping, and payments secure.
The post 7 Tips to Protect Your Smartphone from Getting Hacked appeared first on McAfee Blog.
Introduction In the previous article, we understood how print functions like printf work. This article provides further definition of Format String vulnerabilities. We will begin by discussing how Format Strings can be used in an unusual way, which is a starting point to understanding Format String exploits. Next, we will understand what kind of mistakes […]
The post Format String Vulnerabilities: Use and Definitions appeared first on Infosec Resources.
Introduction In the previous articles, we discussed printing functions, format strings and format string vulnerabilities. This article provides an overview of how Format String vulnerabilities can be exploited. In this article, we will begin by solving a simple challenge to leak a secret from memory. In the next article, we will discuss another example, where […]
The post How to exploit Format String Vulnerabilities appeared first on Infosec Resources.
Introduction: This article provides an overview of various techniques that can be used to mitigate Format String vulnerabilities. In addition to the mitigations that are offered by the compilers & operating systems, we will also discuss preventive measures that can be used while writing programs in languages susceptible to Format String vulnerabilities. Techniques to prevent […]
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