Critical Security Flaw Meltdown and Spectre Explained

Critical Security Flaw Meltdown and Spectre Explained

Meltdown and Spectre are critical security vulnerabilities that affect most modern computer processors and operating systems. These vulnerabilities allow computer programs to steal sensitive data processed on the computer.

Meltdown’s official name is CVE-2017-5754. Spectre is the collective name for 2 vulnerabilities, CVE-2017-5753 and CVE-2017-5715. CVE stands for common vulnerabilities and exposures. It’s a system that provides official references for publicly known cybersecurity vulnerabilities.

A typical computer program isn’t allowed to read data from other computer programs. What Meltdown and Spectre do is access the data stored in the memory of other running computer programs. Data that could be accessed by these vulnerabilities include photos, instant messages, emails and passwords stored in a browser or password manager.

What is Meltdown?

What Meltdown does is break the barrier that isolates computer programs and the operating system. By breaking this barrier, a Meltdown attack could access the operating system and other programs.

Meltdown was independently discovered by security researchers from Google Project Zero, Cyberus Technology and Graz University of Technology.

According to the security researchers who discovered Meltdown, this vulnerability potentially affects every Intel processor which implements “out-of-order execution” meaning, every Intel processor produced since 1995, except Intel Itanium and Intel Atom before 2013. Meltdown has also been shown to potentially affect other processors including ARM and AMD.

Cloud providers which use Intel CPUs and Xen PV and cloud providers without real hardware virtualization may also be potentially affected.

What is Spectre?

What Spectre does is break the barrier that isolates different computer programs. It also tricks a computer program that follows security practices into leaking data.

Spectre was independently discovered by Jann Horn of Google Project Zero and

Paul Kocher.

According to the security researchers who discovered Spectre, almost every modern desktops, laptops, mobile devices and cloud servers are potentially vulnerable. In particular, Intel, AMD and ARM processors are known to be potentially vulnerable to Spectre.

Similarities Between Meltdown and Spectre

Here are the similarities between Meltdown and Spectre:

• Both affect most modern computer chips and operating systems.
• Both could steal sensitive data processed on the computer.
• Both are difficult to detect.

It’s difficult to detect these vulnerabilities as they don’t leave any traces in traditional log files. They’re also difficult to detect as antivirus, for instance, find it hard to distinguish an error-free computer program from Meltdown or Spectre.

Difference Between Meltdown and Spectre

The difference between Meltdown and Spectre is that while Meltdown cracks the barrier that prevents programs from accessing the computer memory, Spectre tricks other computer programs into accessing arbitrary locations in their memory.

Researchers who discovered Meltdown and Spectre said they don’t know whether these vulnerabilities have been exploited into the wild. ProjectZero team at Googlepublicly disclosed these vulnerabilities on January 3, 2018. The team reported these security issues to Intel, AMD and ARM on June 1, 2017.

Intel’s January 2018 press statementstates that the company will issue security updates for at least 90% of Intel CPUs introduced in the last 5 years by January 15, 2018, while security updates for the remaining CPUs will be available by the end of January.

In Intel’s latest press statement, the company said it won’t issue security updates for Spectre for the following processors: Bloomfield line, Clarksfield, Gulftown, Harpertown line, Jasper Forest, Penryn/QC, SoFIA 3GR, Wolfdale line and Yorkfield Line.

Here’s Intel’s explanation why it won't issue security updates of the above-mentioned chips:

“After a comprehensive investigation of the microarchitectures and microcode capabilities for these products, Intel has determined to not release

microcode updates for these products for one or more reasons including, but not limited to the following:

• Micro-architectural characteristics that preclude a practical implementation of features mitigating Variant 2 (CVE-2017-5715)
• Limited Commercially Available System Software support
• Based on customer inputs, most of these products are implemented as ‘closed systems’ and therefore are expected to have a lower likelihood of exposure to these vulnerabilities.”

Most of the above-mentioned unsupported Intel processors are more than 5 years old, some even are more than a decade old, with exception of SoFIA 3GR which was released only in 2015.

According to Microsoft, it has released several security updates to mitigate the effects of Meltdown and Spectre. The company added that it took action to protect its cloud services against these vulnerabilities. “Microsoft has released several updates to help mitigate these vulnerabilities,” Microsoft said in a statement. “We have also taken action to secure our cloud services."

How to Protect Your Organization’s Computers from Meltdown and Spectre

Here are some of the preventive measures to protect your organization’s computers from these vulnerabilities:

• Install security updates.

Meltdown and Spectre affect a number of computer processors, not just Intel. These vulnerabilities also affect operating systems, not just Windows. According to Microsoft, users of Windows operating systems should apply the January and February 2018 Windows security updates as well as the monthly Windows security updates.

• For Windows server operating system, Microsoft recommends making necessary configuration changes to enable protection.

• Avoid unrecognized hyperlinks and websites.

• Avoid downloading files or applications from unknown sources.

• Follow secure password protocols.

• Use security software to help protect against malicious software (malware).

• Consider CPU Options

According to Carnegie Mellon University Software Engineering Institute, there have been reports that the overall CPU performance is impacted by many of the available patches for these vulnerabilities. 

“While we recognize that replacing existing CPUs in already deployed systems is not practical, organizations acquiring new systems should evaluate their CPU selection in light of the expected longevity of this vulnerability in available hardware as well as the performance impacts resulting from the various platform-specific software patches,” Carnegie Mellon University Software Engineering Institute said.