Bug 1810359 (CVE-2020-0550) - CVE-2020-0550 hw: Snoop-Assisted L1D Sampling
Summary: CVE-2020-0550 hw: Snoop-Assisted L1D Sampling
Alias: CVE-2020-0550
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On:
Blocks: 1753462
TreeView+ depends on / blocked
Reported: 2020-03-05 04:25 UTC by Wade Mealing
Modified: 2021-02-16 20:31 UTC (History)
18 users (show)

Fixed In Version:
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Doc Text:
A flaw was found in the Intel CPU's cache coherency mechanism. A microarchitectural (hardware) implementation issue that could allow an unprivileged local attacker to bypass conventional system security controls to infer on-CPU Level 1 cache contents is present. At this time, this specific flaw is only known to affect Intel-based processors. The highest threat from this vulnerability is to data confidentiality.
Clone Of:
Last Closed: 2020-03-10 22:31:49 UTC

Attachments (Terms of Use)

Description Wade Mealing 2020-03-05 04:25:40 UTC
Red Hat is aware of a microarchitectural (hardware) implementation issue that could allow an unprivileged local attacker to bypass conventional system security controls to infer on-CPU Level 1 cache contents.

Intel has stated that this flaw is difficult to exploit and will not be releasing microcode updates to mitigate this issue.  Please contact Intel for further questions.


Comment 3 Wade Mealing 2020-03-09 05:42:20 UTC
Affected CPU releases:

- Legacy Intel Core Processors (Sandy Bridge)
- Intel Xeon Processor family v2 (Sandy Bridge)
- Intel Xeon Processor family v3 (Haswell)
- Intel Xeon Processor family v4 (Broadwell)

Comment 6 Product Security DevOps Team 2020-03-10 22:31:49 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):


Comment 10 Eric Christensen 2020-03-11 14:42:47 UTC

CVE-2020-0550 is the CVE assigned specifically to the hardware implementation leading to this flaw. Unlike the L1TF microarchitectural issue, no additional CVE have been assigned at this time to cover operating systems or vmm/hypervisor specific implementations.

As this CVE is a flaw in specific hardware, not the operating system kernel, and operating system mitigations are already applied, Red Hat does not list the Red Hat Enterprise Linux kernel package as “affected” by this CVE.

This does not imply that the flaw can not be exposed on systems running Red Hat Enterprise Linux on vulnerable hardware, only that the flaw exists in the hardware implementation and no additional changes are deemed necessary or practical to address this flaw at the software layer. 

Existing mitigations released in Red Hat Enterprise Linux in response to Spectre V1 (https://access.redhat.com/security/vulnerabilities/speculativeexecution), L1TF (https://access.redhat.com/security/vulnerabilities/L1TF) and MDS (https://access.redhat.com/security/vulnerabilities/mds) should already provide significant barrier against exploitation of this attack vector and no new mitigation is planned at this time.

Comment 11 Eric Christensen 2020-03-11 20:29:24 UTC

Due to the high level of difficulty of the attack and the performance impact which would be associated with any potential mitigations, there are currently no microcode or software mitigations for this issue, other than the existing L1TF mitigations described above, which protect virtual machines against other virtual machines on the host; and disabling TSX, as described above, which can raise the bar of difficulty of the attack.

Red Hat doesn't currently have knowledge of any real-world occurrences of this attack, so the risk of attack may be considered low. To further minimize the possibility of attacks related to this and other speculative issues, trusted and untrusted workloads can be isolated on separate systems.

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