CVE-2021-47226 Vulnerability Analysis & Exploit Details

CVE-2021-47226
Vulnerability Scoring

Analysis In Progress
Analysis In Progress

Attack Complexity Details

  • Attack Complexity:
    Attack Complexity Analysis In Progress
  • Attack Vector:
    Attack Vector Under Analysis
  • Privileges Required: None
    No authentication is required for exploitation.
  • Scope:
    Impact is confined to the initially vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-47226 Details

Status: Awaiting Analysis

Last updated: 🕡 21 Nov 2024, 06:35 UTC
Originally published on: 🕒 21 May 2024, 15:15 UTC

Time between publication and last update: 183 days

CVSS Release:

CVE-2021-47226 Vulnerability Summary

CVE-2021-47226: In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Invalidate FPU state after a failed XRSTOR from a user buffer Both Intel and AMD consider it to be architecturally valid for XRSTOR to fail with #PF but nonetheless change the register state. The actual conditions under which this might occur are unclear [1], but it seems plausible that this might be triggered if one sibling thread unmaps a page and invalidates the shared TLB while another sibling thread is executing XRSTOR on the page in question. __fpu__restore_sig() can execute XRSTOR while the hardware registers are preserved on behalf of a different victim task (using the fpu_fpregs_owner_ctx mechanism), and, in theory, XRSTOR could fail but modify the registers. If this happens, then there is a window in which __fpu__restore_sig() could schedule out and the victim task could schedule back in without reloading its own FPU registers. This would result in part of the FPU state that __fpu__restore_sig() was attempting to load leaking into the victim task's user-visible state. Invalidate preserved FPU registers on XRSTOR failure to prevent this situation from corrupting any state. [1] Frequent readers of the errata lists might imagine "complex microarchitectural conditions".

Assessing the Risk of CVE-2021-47226

Access Complexity Graph

The exploitability of CVE-2021-47226 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2021-47226

No exploitability data is available for CVE-2021-47226.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2021-47226, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2021-47226, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2021-47226 does not compromise confidentiality.
  • Integrity: None
    CVE-2021-47226 does not impact data integrity.
  • Availability: None
    CVE-2021-47226 does not affect system availability.

Exploit Prediction Scoring System (EPSS)

The EPSS score estimates the probability that this vulnerability will be exploited in the near future.

EPSS Score: 0.045% (probability of exploit)

EPSS Percentile: 18.35% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 81.65% of others.

CVE-2021-47226 References

External References

CWE Common Weakness Enumeration

Unknown

Protect Your Infrastructure against CVE-2021-47226: Combat Critical CVE Threats

Stay updated with real-time CVE vulnerabilities and take action to secure your systems. Enhance your cybersecurity posture with the latest threat intelligence and mitigation techniques. Develop the skills necessary to defend against CVEs and secure critical infrastructures. Join the top cybersecurity professionals safeguarding today's infrastructures.

Other 5 Recently Published CVEs Vulnerabilities

  • CVE-2024-43107 – Improper Certificate Validation (CWE-295) in the Gallagher Milestone Integration Plugin (MIP) permits unauthenticated messages (e.g. alarm events) ...
  • CVE-2024-41724 – Improper Certificate Validation (CWE-295) in the Gallagher Command Centre SALTO integration allowed an attacker to spoof the SALTO server. Thi...
  • CVE-2025-2133 – A vulnerability classified as problematic was found in ftcms 2.1. Affected by this vulnerability is an unknown functionality of the file /admin/ind...
  • CVE-2025-2132 – A vulnerability classified as critical has been found in ftcms 2.1. Affected is an unknown function of the file /admin/index.php/web/ajax_all_lists...
  • CVE-2025-2131 – A vulnerability was found in dayrui XunRuiCMS up to 4.6.3. It has been rated as problematic. This issue affects some unknown processing of the comp...