CVE-2021-22556 Vulnerability Analysis & Exploit Details

CVE-2021-22556
Vulnerability Scoring

5.3
/10
Significant Risk

Security assessments indicate that CVE-2021-22556 presents a notable risk, potentially requiring prompt mitigation.

Attack Complexity Details

  • Attack Complexity: High
    Exploits require significant effort and special conditions.
  • Attack Vector: Local
    Vulnerability requires local system access.
  • Privileges Required: Low
    Some privileges are necessary to exploit the vulnerability.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-22556 Details

Status: Modified

Last updated: 🕠 21 Nov 2024, 05:50 UTC
Originally published on: 🕓 03 May 2022, 16:15 UTC

Time between publication and last update: 932 days

CVSS Release: version 3

CVSS3 Source

cve-coordination@google.com

CVSS3 Type

Secondary

CVSS3 Vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N

CVE-2021-22556 Vulnerability Summary

CVE-2021-22556: The Security Team discovered an integer overflow bug that allows an attacker with code execution to issue memory cache invalidation operations on pages that they don’t own, allowing them to control kernel memory from userspace. We recommend upgrading to kernel version 4.1 or beyond.

Assessing the Risk of CVE-2021-22556

Access Complexity Graph

The exploitability of CVE-2021-22556 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-2021-22556

This vulnerability, CVE-2021-22556, requires a high level of attack complexity and low privileges, making it difficult but not impossible to exploit. Organizations should ensure robust security configurations to mitigate risks.

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-2021-22556, 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-2021-22556, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: High
    Exploiting CVE-2021-22556 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: Low
    Exploiting CVE-2021-22556 may cause minor changes to data without severely impacting its accuracy.
  • Availability: None
    CVE-2021-22556 does not impact 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: 0.089% (probability of exploit)

EPSS Percentile: 40.49% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 59.51% of others.

CVE-2021-22556 References

External References

CWE Common Weakness Enumeration

CWE-190

CAPEC Common Attack Pattern Enumeration and Classification

  • Forced Integer Overflow CAPEC-92 This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.

Vulnerable Configurations

  • cpe:2.3:o:google:fuchsia:-:*:*:*:*:*:*:*
    cpe:2.3:o:google:fuchsia:-:*:*:*:*:*:*:*

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