Russell Coker, a senior developer with the Debian GNU/Linux project and a tech consultant, told iTWire: "In many cases, [this] means buying a new PC given that there aren't many options for replacing a CPU in some systems and for others replacing the CPU may take more time and effort than just buying a new system."

He was commenting on a recent report that the first working Linux exploit for Spectre had been found. Spectre, a flaw present in Intel processors made since 1995, can allow vulnerable applications to be tricked into leaking the contents of their memory.

Intel was forced to go public with the bug after an embargo set by Google researchers, who discovered the flaw, was broken before the agreed date of 9 January 2018.

Debian includes a program called spectre-meltdown-checker that users can run to find out if their systems are vulnerable to this bug.

Russell said he had run this program on all the physical servers he was responsible for and also on his own laptop.

"Of 11 systems, only two are given the all-clear by spectre-meltdown-checker even though they all have hyper-threading turned off," he said.

"A look at the results shows that server class systems are vulnerable to fewer issues and most of the issues are due to Intel not releasing microcode updates (or not being able to fix some issues on a particular CPU)."

The author, who also uses Debian, ran the program on his workstation and laptop; the former has an AMD Ryzen 5 from 2019 and the latter an Intel i7 from 2014.

The output is given under:

Laptop:

Checking for vulnerabilities on current system

Kernel is Linux 5.10.0-3-amd64 #1 SMP Debian 5.10.13-1 (2021-02-06) x86_64

CPU is Intel(R) Core(TM) i7-3632QM CPU @ 2.20GHz

CPU vulnerability to the speculative execution attack variants

• * Vulnerable to CVE-2017-5753 (Spectre Variant 1, bounds check bypass): YES
• * Vulnerable to CVE-2017-5715 (Spectre Variant 2, branch target injection): YES
• * Vulnerable to CVE-2017-5754 (Variant 3, Meltdown, rogue data cache load): YES
• * Vulnerable to CVE-2018-3640 (Variant 3a, rogue system register read): YES
• * Vulnerable to CVE-2018-3639 (Variant 4, speculative store bypass): YES
• * Vulnerable to CVE-2018-3615 (Foreshadow (SGX), L1 terminal fault): NO
• * Vulnerable to CVE-2018-3620 (Foreshadow-NG (OS), L1 terminal fault): YES
• * Vulnerable to CVE-2018-3646 (Foreshadow-NG (VMM), L1 terminal fault): YES
• * Vulnerable to CVE-2018-12126 (Fallout, microarchitectural store buffer data sampling (MSBDS)): YES
• * Vulnerable to CVE-2018-12130 (ZombieLoad, microarchitectural fill buffer data sampling (MFBDS)): YES
• * Vulnerable to CVE-2018-12127 (RIDL, microarchitectural load port data sampling (MLPDS)): YES
• * Vulnerable to CVE-2019-11091 (RIDL, microarchitectural data sampling uncacheable memory (MDSUM)): YES
• * Vulnerable to CVE-2019-11135 (ZombieLoad V2, TSX Asynchronous Abort (TAA)): NO
• * Vulnerable to CVE-2018-12207 (No eXcuses, iTLB Multihit, machine check exception on page size changes (MCEPSC)): YES
• * Vulnerable to CVE-2020-0543 (Special Register Buffer Data Sampling (SRBDS)): YES

Workstation:

Checking for vulnerabilities on current system

Kernel is Linux 5.10.0-3-amd64 #1 SMP Debian 5.10.13-1 (2021-02-06) x86_64

CPU is AMD Ryzen 5 2600 Six-Core Processor

• * CPU vulnerability to the speculative execution attack variants
• * Vulnerable to CVE-2017-5753 (Spectre Variant 1, bounds check bypass): YES
• * Vulnerable to CVE-2017-5715 (Spectre Variant 2, branch target injection): YES
• * Vulnerable to CVE-2017-5754 (Variant 3, Meltdown, rogue data cache load): NO
• * Vulnerable to CVE-2018-3640 (Variant 3a, rogue system register read): NO
• * Vulnerable to CVE-2018-3639 (Variant 4, speculative store bypass): YES
• * Vulnerable to CVE-2018-3615 (Foreshadow (SGX), L1 terminal fault): NO
• * Vulnerable to CVE-2018-3620 (Foreshadow-NG (OS), L1 terminal fault): NO
• * Vulnerable to CVE-2018-3646 (Foreshadow-NG (VMM), L1 terminal fault): NO
• * Vulnerable to CVE-2018-12126 (Fallout, microarchitectural store buffer data sampling (MSBDS)): NO
• * Vulnerable to CVE-2018-12130 (ZombieLoad, microarchitectural fill buffer data sampling (MFBDS)): NO
• * Vulnerable to CVE-2018-12127 (RIDL, microarchitectural load port data sampling (MLPDS)): NO
• * Vulnerable to CVE-2019-11091 (RIDL, microarchitectural data sampling uncacheable memory (MDSUM)): NO
• * Vulnerable to CVE-2019-11135 (ZombieLoad V2, TSX Asynchronous Abort (TAA)): NO
• * Vulnerable to CVE-2018-12207 (No eXcuses, iTLB Multihit, machine check exception on page size changes (MCEPSC)): NO
• * Vulnerable to CVE-2020-0543 (Special Register Buffer Data Sampling (SRBDS)): NO

Said Russell: "So if you don't want to spend money on upgrading your hardware it seems that you have to hope that no-one exploits the sandbox process of your Web browser, the privsep process of sshd, or any of the other programs that are the first line of defence against hostile code.

"The Spectre family of vulnerabilities has the potential to turn minor security issues into root exploits. As the vast majority of computers connect to the Internet and have potentially buggy code handling data from the Internet, this is a real risk.

"Just buying AMD would be a nice option, but it seems that Intel has the dominant market share of laptops. Also if you want to get affordable servers second-hand then you will probably end up with Intel CPUs."