Using Components with Known Vulnerabilities

While it is easy to find already-written exploits for many known vulnerabilities, other vulnerabilities require concentrated effort to develop a custom exploit.

Is the Application Vulnerable?

You are likely vulnerable:

• If you do not know the versions of all components you use (both client-side and server-side). This includes components you directly use as well as nested dependencies.

• If software is vulnerable, unsupported, or out of date. This includes the OS, web/application server, database management system (DBMS), applications, APIs and all components, runtime environments, and libraries.

• If you do not scan for vulnerabilities regularly and subscribe to security bulletins related to the components you use.

• If you do not fix or upgrade the underlying platform, frameworks, and dependencies in a risk-based, timely fashion. This commonly happens in environments when patching is a monthly or quarterly task under change control, which leaves organizations open to many days or months of unnecessary exposure to fixed vulnerabilities.

• If software developers do not test the compatibility of updated, upgraded, or patched libraries.

• If you do not secure the components' configurations (see A6:2017-Security Misconfiguration).

How to Prevent

There should be a patch management process in place to:

• Remove unused dependencies, unnecessary features, components, files, and documentation.

• Continuously inventory the versions of both client-side and server-side components (e.g. frameworks, libraries) and their dependencies using tools like versions, DependencyCheck, retire.js, etc. Continuously monitor sources like CVE and NVD for vulnerabilities in the components. Use software composition analysis tools to automate the process. Subscribe to email alerts for security vulnerabilities related to components you use.

• Only obtain components from official sources over secure links. Prefer signed packages to reduce the chance of including a modified, malicious component.

• Monitor for libraries and components that are unmaintained or do not create security patches for older versions. If patching is not possible, consider deploying a virtual patch to monitor, detect, or protect against the discovered issue.

Every organization must ensure that there is an ongoing plan for monitoring, triaging, and applying updates or configuration changes for the lifetime of the application or portfolio.

Example Attack Scenarios

Scenario #1:

Components typically run with the same privileges as the application itself, so flaws in any component can result in serious impact. Such flaws can be accidental (e.g. coding error) or intentional (e.g. backdoor in component). Some example exploitable component vulnerabilities discovered are:

• CVE-2017-5638, a Struts 2 remote code execution vulnerability that enables execution of arbitrary code on the server, has been blamed for significant breaches.

• While internet of things (IoT) are frequently difficult or impossible to patch, the importance of patching them can be great (e.g. biomedical devices).

There are automated tools to help attackers find unpatched or misconfigured systems. For example, the Shodan IoT search engine can help you find devices that still suffer from the Heartbleed vulnerability that was patched in April 2014.

Example Attack Scenarios - Heartbleed
Heartbleed a flaw in the OpenSSL cryptographic software library discovered in 2014. This software component, whose main purpose is to protect data on web applications, had a security weakness allowing attackers to steal the information usually protected by SSL/TLS encryption. This bug allowed anyone on the Internet to read the memory of systems protected by the vulnerable versions of the OpenSSL software, compromising secret keys used to identify service providers and encrypt the traffic, names and passwords of users and the actual content. By eavesdropping on communications, attackers could steal data directly or even impersonate the services or users. At the time this issue was discovered, half a million widely trusted websites were vulnerable to the Heartbleed bug. As of early 2017, a great number of companies (about 200,000) were still using a component with a known vulnerability.

Próximo

Anterior