{"id":104416,"date":"2022-06-15T15:36:54","date_gmt":"2022-06-15T13:36:54","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/hertzbleed-novoe-semejstvo-atak-po-storonnim-kanalam-zatragivayushhee-sovremennye-cpu"},"modified":"2022-06-15T15:36:54","modified_gmt":"2022-06-15T13:36:54","slug":"hertzbleed-novoe-semejstvo-atak-po-storonnim-kanalam-zatragivayushhee-sovremennye-cpu","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/news\/hertzbleed-novoe-semejstvo-atak-po-storonnim-kanalam-zatragivayushhee-sovremennye-cpu","title":{"rendered":"Hertzbleed \u2014 a new family of side-channel attacks affecting modern CPUs","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
A group of researchers from the universities of Texas, Illinois, and Washington has revealed information about a new family of side-channel attacks (CVE-2022-23823, CVE-2022-24436) code-named Hertzbleed. The proposed attack method is based on the peculiarities of dynamic frequency scaling in modern processors and affects all current Intel and AMD CPUs. The problem may potentially also arise in processors from other manufacturers that support dynamic frequency adjustment, such as ARM systems, but the research conducted was limited to testing Intel and AMD chips. The source code implementing the attack method has been published on GitHub (the implementation was tested on a computer with an Intel i7-9700 CPU). <\/p>\n
To optimize energy consumption and prevent overheating, processors dynamically adjust their frequency based on load, which affects performance and impacts operation execution time (a frequency change of 1 Hz leads to a performance change of 1 cycle per second). The research has shown that under certain conditions on AMD and Intel processors, frequency changes directly correlate with the data being processed, resulting in differences in computation times for operations like '2022 + 23823' and '2022 + 24436'. Based on the analysis of execution time differences with varying data, information used during computations can be indirectly reconstructed. In high-speed networks with predictable constant delays, an attack can be conducted remotely by measuring the execution time of requests. <\/p>\n
If the attack is successful, the identified issues allow for the determination of private keys based on the analysis of computation times in cryptographic libraries that use algorithms where mathematical calculations are always executed in constant time, regardless of the nature of the processed data. Such libraries were considered secure against side-channel attacks, but it turns out that computation time is influenced not only by the algorithm but also by the characteristics of the processor's operation. <\/p>\n
As a practical example demonstrating the feasibility of the proposed method, an attack on the SIKE (Supersingular Isogeny Key Encapsulation) key encapsulation mechanism was demonstrated. This mechanism reached the finals of the post-quantum cryptosystems competition held by the National Institute of Standards and Technology (NIST) and is positioned as resistant to side-channel attacks. In the experiment, a new variant of the attack based on chosen ciphertext (gradual selection through manipulation of the encrypted text and obtaining its decryption) managed to fully recover the encryption key while conducting measurements from a remote system, despite the use of a SIKE implementation with constant computation time. It took 36 hours to determine a 364-bit key using the CIRCL implementation, while PQCrypto-SIDH required 89 hours. <\/p>\n
Both Intel and AMD have acknowledged the vulnerability in their processors but do not plan to mitigate it through microcode updates, as it cannot be hardware-fixed without significantly impacting performance. Instead, developers of cryptographic libraries have been given recommendations for software-based blocking of information leaks during sensitive computations. Companies like Cloudflare and Microsoft have already integrated such protections into their SIKE implementations, resulting in a performance decrease of 5% for CIRCL and 11% for PQCrypto-SIDH. Another workaround for blocking the vulnerability in the BIOS or driver is to disable the modes 'Turbo Boost', 'Turbo Core', or 'Precision Boost', but this change will lead to a drastic reduction in performance. <\/p>\n
Intel, Cloudflare, and Microsoft were informed of the issue in the third quarter of 2021, while AMD was notified in the first quarter of 2022. However, at Intel's request, the public disclosure of the issue was postponed until June 14, 2022. The existence of the problem has been confirmed in processors for desktop systems and laptops based on 8th to 11th generation Intel Core microarchitecture, as well as for various desktop, mobile, and server processors including AMD Ryzen, Athlon, A-Series, and EPYC (researchers demonstrated the method on Ryzen CPUs with Zen 2 and Zen 3 microarchitecture). \n Source: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"