kraven + tech_hw_chip_cpu   4

Spectre chip security vulnerability strikes again; patches incoming
Jann Horn, a Google Project Zero security researcher, discovered this not long after the first Spectre holes were patched. Horn found a new way to attack microprocessors, which use Spectre-like speculative execution and speculative execution of memory reads before the addresses of all prior memory writes are known. With this, and armed with the right code, a local user can pull data from a system using a side-channel analysis. In short, it could allow unauthorized read access to memory on almost any 21st century processor. The Common Vulnerability and Exposures (CVE) number for this security problem is CVE-2018-3639. Intel calls this a Speculative Store Bypass (SSB), also known as Spectre Variant 4. Unlike the bug discovered by Yuriy Bulygin [NB: https://pinboard.in/u:kraven/b:c7835072bdd1], the former head of Intel's advanced threat team, who showed that the older Spectre CPU flaws could be used to break into the Intel x86 systems' System Management Mode (SMM), SBB is a new method. Another new but less dangerous Spectre-style security hole is CVE-2018-3640, aka Rogue System Register Read (RSRE), or Spectre Variant 3a. This one can impact systems with microprocessors utilizing speculative execution that perform speculative reads of system registers. With this, local users may be able to get unauthorized disclosure of system parameters via a side-channel analysis.
zdnet, 22.05.2018
itsicherheit_exploit_flaw  tech_hw_chip_cpu  itsicherheit_seitenkanal_analyse_angriff  itsicherheit_cpu_meltdown_spectre  itsicherheit_hardware 
may 2018 by kraven
Super-GAU für Intel: Weitere Spectre-Lücken im Anflug
Ganze acht neue Sicherheitslücken in Intel-CPUs haben mehrere Forscher-Teams dem Hersteller bereits gemeldet, die aktuell noch geheimgehalten werden. Alle acht sind im Kern auf dasselbe Design-Problem zurückzuführen, das der Abschnitt "Meltdown und Spectre für Dummies" näher erläutert – sie sind sozusagen Spectre Next Generation. Jede der acht Lücken hat eine eigene Nummer im Verzeichnis aller Sicherheitslücken bekommen (Common Vulnerability Enumerator, CVE) und jede erfordert eigene Patches – wahrscheinlich bekommen sie auch alle eigene Namen. Konkrete Informationen liegen uns bisher nur zu Intels Prozessoren und deren Patch-Plänen vor. Es gibt jedoch erste Hinweise, dass zumindest einzelne ARM-CPUs ebenfalls anfällig sind. Vier der Spectre-NG-Sicherheitslücken stuft Intel selbst mit einem "hohen Risiko" ein; die Gefahr der anderen vier ist lediglich als mittel bewertet. Eine der Spectre-NG-Lücken vereinfacht Angriffe über Systemgrenzen hinweg so stark, dass wir das Bedrohungspotential deutlich höher einschätzen als bei Spectre. Konkret könnte ein Angreifer seinen Exploit-Code in einer virtuellen Maschine (VM) starten und von dort aus das Wirts-System attackieren – also etwa den Server eines Cloud-Hosters. Oder er greift die auf dem gleichen Server laufenden VMs anderer Kunden an.
ct, 03.05.2018
itsicherheit_cpu_meltdown_spectre  itsicherheit_exploit_flaw  itsicherheit_hardware  itsicherheit_implementierung  tech_hw_chip_cpu  tech_hw_chip_cpu_cache  unternehmen_amd  unternehmen_intel  unternehmen_allg_desinformation_propaganda  itsicherheit_by_obscurity  itsicherheit_virtualisierung  itsicherheit_seitenkanal_analyse_angriff 
may 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
Reading privileged memory with a side-channel
We have discovered that CPU data cache timing can be abused to efficiently leak information out of mis-speculated execution, leading to (at worst) arbitrary virtual memory read vulnerabilities across local security boundaries in various contexts. Variants of this issue are known to affect many modern processors, including certain processors by Intel, AMD and ARM. For a few Intel and AMD CPU models, we have exploits that work against real software. So far, there are three known variants of the issue: Variant 1: bounds check bypass (CVE-2017-5753), Variant 2: branch target injection (CVE-2017-5715), Variant 3: rogue data cache load (CVE-2017-5754). Before the issues described here were publicly disclosed, Daniel Gruss, Moritz Lipp, Yuval Yarom, Paul Kocher, Daniel Genkin, Michael Schwarz, Mike Hamburg, Stefan Mangard, Thomas Prescher and Werner Haas also reported them; their [writeups/blogposts/paper drafts] are at: Spectre (variants 1 and 2), Meltdown (variant 3) [NB: Fuck you Intel, mein nxter Rechner wird non-intel].
google project zero, 03.01.2018
itsicherheit_exploit_flaw  itsicherheit_malware_spyware  itsicherheit_speicher_aslr  itsicherheit_hardware  itsicherheit_implementierung  itsicherheit_os  unternehmen_intel  sicherheitsforschung_itsicherheit  software_os_linux  software_os_windows  software_os_mac  software_os_kernel  unternehmen_amd  unternehmen_arm  tech_hw_chip_cpu  tech_hw_chip_cpu_cache  itsicherheit_cpu_meltdown_spectre  itsicherheit_seitenkanal_analyse_angriff 
january 2018 by kraven

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