CVE-2021-25736 Vulnerability Analysis & Exploit Details

CVE-2021-25736
Vulnerability Scoring

5.8
/10
Significant Risk

Security assessments indicate that CVE-2021-25736 presents a notable risk, potentially requiring prompt mitigation.

Attack Complexity Details

  • Attack Complexity: High
    Exploits require significant effort and special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: High
    High-level privileges are required for exploitation.
  • Scope: Changed
    Successful exploitation can impact components beyond the vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-25736 Details

Status: Modified

Last updated: 🕔 13 Feb 2025, 17:15 UTC
Originally published on: 🕒 30 Oct 2023, 03:15 UTC

Time between publication and last update: 472 days

CVSS Release: version 3

CVSS3 Source

jordan@liggitt.net

CVSS3 Type

Secondary

CVSS3 Vector

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

CVE-2021-25736 Vulnerability Summary

CVE-2021-25736: Kube-proxy on Windows can unintentionally forward traffic to local processes listening on the same port (“spec.ports[*].port”) as a LoadBalancer Service when the LoadBalancer controller does not set the “status.loadBalancer.ingress[].ip” field. Clusters where the LoadBalancer controller sets the “status.loadBalancer.ingress[].ip” field are unaffected.

Assessing the Risk of CVE-2021-25736

Access Complexity Graph

The exploitability of CVE-2021-25736 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-2021-25736

The exploitability of CVE-2021-25736 is influenced by multiple factors. Security teams should analyze system configurations and apply appropriate countermeasures to mitigate threats.

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-2021-25736, 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-2021-25736, 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-2021-25736 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: None
    CVE-2021-25736 poses no threat to data integrity.
  • Availability: None
    CVE-2021-25736 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: 0.122% (probability of exploit)

EPSS Percentile: 48.07% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 51.93% of others.

CVE-2021-25736 References

External References

CWE Common Weakness Enumeration

NVD-CWE-noinfo

Vulnerable Configurations

  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:rc1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:rc1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:beta0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:beta0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:beta1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:beta1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:beta2:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:beta2:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha2:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha2:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha3:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha3:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha4:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha4:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha5:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.0:alpha5:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.1:beta0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.1:beta0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.2:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.2:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.2:beta0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.2:beta0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.3:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.3:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.3:beta0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.3:beta0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.4:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.4:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.4:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.4:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.5:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.5:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.5:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.5:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.5:rc1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.5:rc1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.6:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.6:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.6:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.6:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.7:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.7:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.7:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.7:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.8:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.8:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.8:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.8:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.8:rc1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.8:rc1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.9:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.9:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.9:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.9:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.10:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.10:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.10:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.10:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.18.17:*:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.18.17:*:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc2:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc2:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc3:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc3:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc4:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:rc4:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:beta0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:beta0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:beta1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:beta1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:beta2:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:beta2:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:alpha0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:alpha0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:alpha1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:alpha1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:alpha2:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:alpha2:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.0:alpha3:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.0:alpha3:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.1:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.1:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.1:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.1:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.2:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.2:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.2:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.2:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.3:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.3:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.3:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.3:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.4:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.4:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.4:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.4:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.5:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.5:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.5:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.5:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.6:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.6:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.6:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.6:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.6:rc1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.6:rc1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.7:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.7:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.7:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.7:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.8:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.8:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.8:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.8:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.9:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.9:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.19.9:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.19.9:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:beta0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:beta0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:beta1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:beta1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:beta2:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:beta2:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:alpha0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:alpha0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:alpha1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:alpha1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:alpha2:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:alpha2:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.0:alpha3:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.0:alpha3:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.1:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.1:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.1:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.1:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.1:rc1:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.1:rc1:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.2:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.2:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.2:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.2:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.3:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.3:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.3:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.3:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.4:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.4:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.4:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.4:rc0:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.5:-:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.5:-:*:*:*:*:*:*
  • cpe:2.3:a:kubernetes:kubernetes:1.20.5:rc0:*:*:*:*:*:*
    cpe:2.3:a:kubernetes:kubernetes:1.20.5:rc0:*:*:*:*:*:*
  • cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*
    cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*

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