kraven + tech_hw_chip_intel_sgx   3

Three more data-leaking security holes found in Intel chips as designers swap security for speed
Intel will today disclose three more vulnerabilities in its processors that can be exploited by malware and malicious virtual machines to potentially steal secret information from computer memory. These secrets can include passwords, personal and financial records, and encryption keys. They can be potentially lifted from other applications and other customers' virtual machines, as well as SGX enclaves, and System Management Mode (SMM) memory. SGX is Intel's technology that is supposed to protect these secrets from snooping code. SMM is your computer's hidden janitor that has total control over the hardware, and total access to its data. Across the board, Intel's desktop, workstation, and server CPUs are vulnerable. Crucially, they do not work as documented: where their technical manuals say memory can be marked off limits, it simply is not. This means malicious software on a vulnerable machine, and guest virtual machines on a cloud platform, can potentially lift sensitive data from other software and other customers' virtual machines. Here are the three cockups, which Intel has dubbed its L1 Terminal Fault (L1TF) bugs because they involve extracting secret information from the CPU level-one data cache: CVE-2018-3615: This affects Software Guard Extensions (SGX). This vulnerability was named Foreshadow by the team who uncovered it. CVE-2018-3620: This affects operating systems and SMM. CVE-2018-3646: This affects hypervisors and virtual machines. The upshot is malware or a malicious guest operating system can exploit this to ascertain data it shouldn't be able to read, by forcing pages to be marked as not present and observing what's fetched speculatively from the L1 cache before the page fault circuitry in the processor can step in and halt proceedings. This requires the exploit code to run on the same physical CPU core as the victim code, because it needs to observe the L1 data cache.
register, 14.08.2018
unternehmen_intel  itsicherheit_cpu_meltdown_spectre  itsicherheit_seitenkanal_analyse_angriff  tech_hw_chip_cpu_smm_smi  tech_hw_chip_intel_sgx  tech_virtualisierung  tech_hw_chip_cpu_cache  itsicherheit_by_obscurity  itsicherheit_malware_spyware  itsicherheit_exploit_flaw 
august 2018 by kraven
Researchers Detail New CPU Side-Channel Attack Named SpectreRSB
Academics from the University of California, Riverside (UCR) have published details last week about a new Spectre-class attack that they call SpectreRSB. The difference from previous Spectre-like attacks is that SpectreRSB recovers data from the speculative execution process by attacking a different CPU component involved in this "speculation" routine, namely the Return Stack Buffer (RSB). In the grand architecture of a CPU, the RSB is a component that is involved in the speculative execution routine and works by predicting the return address of an operation the CPU is trying to compute in advance, part of its "speculation." In a research paper published last week, UCR researchers said the could pollute the RSB code to control the return address and poison a CPU's speculative execution routine. For example, in two attacks, they polluted the RSB to expose and recover data from other applications running on the same CPU, and in a third, they polluted the RSB "to cause a misspeculation that exposes data outside an SGX compartment." Researchers said they reported the issue to Intel, but also to AMD and ARM.
bleeping computer, 23.07.2018
itsicherheit_cpu_meltdown_spectre  itsicherheit_exploit_flaw  itsicherheit_seitenkanal_analyse_angriff  tech_hw_chip_intel_sgx  unternehmen_intel  unternehmen_amd  unternehmen_arm  uni_us_uc_riverside 
july 2018 by kraven
As predicted, more branch prediction processor attacks are discovered
Researchers from the College of William and Mary, Carnegie Mellon, the University of California Riverside, and Binghamton University have described a security attack that uses the speculative execution features of modern processors to leak sensitive information and undermine the security boundaries that operating systems and software erect to protect important data. The new attack, named BranchScope by the researchers, shares some similarity with variant 2 of the Spectre attack, as both BranchScope and Spectre 2 take advantage of the behavior of the processor's branch predictor. BranchScope and Spectre 2 both take advantage of different parts of the branch predictor. Spectre 2 relied on a part called the Branch Target Buffer (BTB)—the data structure within the processor that records the branch target. BranchScope, instead, leaks information using the direction of the prediction—whether it's likely to be taken or not—which is stored in the pattern history table (PHT). The researchers looked only at Intel processors, using the attacks to leak information protected using Intel's SGX (Software Guard Extensions), a feature found on certain chips to carve out small sections of encrypted code and data such that even the operating system (or virtualization software) cannot access it. They also described ways the attack could be used against address space layout randomization and to infer data in encryption and image libraries. Spectre 2 has provoked both operating system and hardware changes, with more hardware fixes planned. The researchers suggest that a similar combination of solutions would be needed for BranchScope; some software can be modified to eliminate branches, and hardware could be altered to partition the speculative execution data structures on the processor so that one process could not attack another.
ars technica, 26.03.2018
itsicherheit_cpu_branchscope  tech_hw_chip_intel_sgx  tech_hw_chip_cpu  uni_allg_diverse  itsicherheit_exploit_flaw  itsicherheit_seitenkanal_analyse_angriff 
march 2018 by kraven

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