What is a CVE?
CVE, which stands for Common Vulnerabilities and Exposures, is like a secret agent code for security vulnerabilities in software and hardware products. It’s a standardized system that gives these vulnerabilities their own special identification.
The purpose of CVE is to create a common language for discussing and sharing information about security vulnerabilities, bringing organizations, vendors, and researchers together to tackle security threats as a team.
💡Did you know? Each CVE gets its own unique identifier, a CVE-Id. It follows a format like “CVE-YYYY-NNNN,” where “YYYY” is the year of the assignment and “NNNN” is a sequential number. For example, CVE-2023-1234. By misuse of language, CVE” and “CVE-Id” are often confused.
Linux vulnerability: CVE specific to Linux systems
Linux has its own set of CVEs, referring to security vulnerabilities found within Linux operating systems. They keep developers and users on their toes, making sure they’re aware of potential threats and prioritizing the most critical security updates for their Linux systems.
How can I monitor my Linux vulnerability? The 4 key steps to follow
1. Generate your Software Bill of Material (SBOM)
The primary objective lies in identifying all the software components present within your Linux system, a task referred to as a Software Bill of Material (SBOM). It is essential to have a comprehensive SBOM that lists all the components in your system image along with their configuration details.
Now, the question arises: How do I generate this SBOM? While there are solutions provided by the Yocto Project to enumerate all the software components, they can often result in numerous false positives, making the process less satisfactory. However, other solutions offer more exhaustive SBOMs and even provide insights into the kernel’s configuration, such as CVE Scan by The Embedded Kit.
Once you have your SBOM, you can then proceed to identify all the CVEs that apply to your system. A precise SBOM is the key to optimizing the analysis process.
2. Identify all the CVEs that apply to your system
You have two ways to analyze your Linux CVEs once your SBOM is in hand:
- Manually, using public databases like the National Vulnerability Database (NVD) provided by the National Institute of Standards and Technology (NIST). It lists CVEs for various software and operating systems, including our beloved Linux. This work can be very long and tedious.
- Fortunately, Linux vulnerability monitoring tools like CVE Scan can help you with that. They’ll help you establish your Linux vulnerability list automatically, on a daily basis, to keep a watchful eye, simply, on any critical security breaches your system may have.
3. Analyze your CVEs
But you’ll only be halfway to system cybersecurity. And even if the CVE analysis phase is time-consuming, it remains essential.
To analyze CVEs effectively, it’s crucial to delve into the descriptions and references provided for each entry in public databases. Within CVE listings, you’ll often find links that redirect you to additional sources of information related to that specific vulnerability. Some of these links can even provide a proof of concept, illustrating how the vulnerability can be exploited to mount an attack, often tagged “exploit.”
However, it’s important to note that, in general, the information available in these databases is highly concise. To gain a deeper understanding of a CVE and its potential implications, conducting additional research becomes imperative.
Here is a way to analyze your CVE:
- First and foremost, you need to filter out false positives, which means eliminating components that are not actually embedded in your product.
- Additionally, it’s crucial to exclude components for which there is no known attack vector (i.e., the product does not provide a means for exploiting that vulnerability). However, it’s important to remain vigilant, as a new CVE in the future might open up an attack path unexpectedly.
- The third scenario for eliminating CVEs is when they have no impact on the product, and this sorting is based on our initial risk analysis.
- Finally, sometimes we may find ourselves in a situation where we simply don’t have enough information: no published exploit, insufficient details, etc. If a patch is available, we can apply it, but if not, monitoring becomes imperative.
Tools like CVE Scan provide the means to add annotations to each CVE, allowing us to track all these elements as we conduct successive scans.
An example of exploit available for a Linux vulnerability (CVE).
4. Update your system and apply patches (when possible)
For each critical CVE, you’ll need to find a solution to remove the security breach. For this, several solutions are available:
- Apply an already available update to correct the CVE
- Cherry pick and backport a patch from the mainline development branch to your specific branch. When backporting a patch, you can publish it so that everybody benefits from it.
- If no patch is available, you can accept the risk and continue to closely monitor the CVE or find a workaround like disabling a specific product feature.
5 reasons why you should monitor your Linux vulnerability
🔒 Maintain your Linux system security:
You don’t want any unwanted intruders sneaking in and causing havoc in your system (unauthorized access, compromised device integrity, disrupted system operations, etc.). By addressing your Linux CVEs promptly, you can minimize the risk of security breaches and keep your systems fortified. Learn more about the process to maintain it.
✅ Comply with industry standards:
Many industries and regulatory frameworks require organizations to maintain secure systems. And this is becoming increasingly common (as with the Cyber Resilience Act in Europe). By fixing critical CVE vulnerabilities, you’re showing that you’ve got it all under control and meeting those cybersecurity requirements like a champ.
⚖️ Ensure your system stability:
Unresolved CVE vulnerabilities can lead to all sorts of chaos—system instability, crashes, and unexpected behaviors. You can avoid those and keep your Linux system running smoothly with regular patches and updates.
🤝 Build trust with customers:
Telling them, “Hey, we’re committed to protecting your data and maintaining a secure environment.”
🦸♀️ Contribute to the broader security community:
By sharing your knowledge and helping improve the overall security of the embedded Linux ecosystem.
