CVE-2021-33120
Description
A flaw was found in microcode. An out-of-bounds read under a complex microarchitectural condition in the memory subsystem for some Intel Atom(R) Processors may allow an authenticated user to potentially enable information disclosure or cause a denial of service via network access.
Statement
Red Hat has very limited to no visibility and control over binary blobs provided by third-party vendors. Red Hat relies heavily on the vendors to provide timely updates and information about included changes for this content and in most cases merely acts as a release vehicle between the third-party vendor and Red Hat customers with no possibility of influencing or even documenting the changes. Unless explicitly stated, the level of insight, oversight, and control Red Hat has does not meet the criteria required (in terms of Red Hat owned development processes and QA, documentation) for releasing this content as RHSA. For more information please contact the binary content vendor.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.6 | 5.4 | N/A |
| Attack Vector | Local | Network | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | Low | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | Low | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L
NVD: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
Acknowledgements
Red Hat would like to thank Intel for reporting this issue.
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