CVE-2021-42654 Vulnerability Analysis & Exploit Details

CVE-2021-42654
Vulnerability Scoring

9.8
/10
Critical Risk

As a catastrophic security flaw, CVE-2021-42654 has severe implications, demanding immediate intervention.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: None
    No privileges are required for exploitation.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-42654 Details

Status: Modified

Last updated: 🕕 21 Nov 2024, 06:27 UTC
Originally published on: 🕐 24 May 2022, 13:15 UTC

Time between publication and last update: 911 days

CVSS Release: version 3

CVSS3 Source

nvd@nist.gov

CVSS3 Type

Primary

CVSS3 Vector

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

CVE-2021-42654 Vulnerability Summary

CVE-2021-42654: SiteServer CMS < V5.1 is affected by an unrestricted upload of a file with dangerous type (getshell), which could be used to execute arbitrary code.

Assessing the Risk of CVE-2021-42654

Access Complexity Graph

The exploitability of CVE-2021-42654 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-2021-42654

With low attack complexity and no required privileges, CVE-2021-42654 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.

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-2021-42654, 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-2021-42654, 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-2021-42654 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: High
    CVE-2021-42654 could allow unauthorized modifications to data, potentially affecting system reliability and trust.
  • Availability: High
    CVE-2021-42654 can disrupt system operations, potentially causing complete denial of service (DoS).

Exploit Prediction Scoring System (EPSS)

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

EPSS Score: 0.341% (probability of exploit)

EPSS Percentile: 71.73% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 28.269999999999996% of others.

CVE-2021-42654 References

External References

CWE Common Weakness Enumeration

CWE-434

CAPEC Common Attack Pattern Enumeration and Classification

  • Accessing Functionality Not Properly Constrained by ACLs CAPEC-1 In applications, particularly web applications, access to functionality is mitigated by an authorization framework. This framework maps Access Control Lists (ACLs) to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application, or can run queries for data that they otherwise not supposed to.

Vulnerable Configurations

  • cpe:2.3:a:sscms:siteserver_cms:5.0.15:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.15:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.18:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.18:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.22:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.22:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.23:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.23:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.24:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.24:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.25:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.25:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.27:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.27:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.33:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.33:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.34:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.34:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.36:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.36:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.37:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.37:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.39:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.39:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.40:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.40:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.48:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.48:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.51:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.51:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.53:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.53:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.55:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.55:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.56:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.56:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.57:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.57:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.59:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.59:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.61:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.61:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.62:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.62:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.63:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.63:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.69:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.69:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.70:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.70:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.76:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.76:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.78:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.78:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.80:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.80:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.81:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.81:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.82:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.82:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.85:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.85:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.86:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.86:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.87:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.87:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.89:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.89:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.91:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.91:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.92:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.92:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.94:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.94:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.95:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.95:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.97:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.97:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.101:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.101:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.102:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.102:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.103:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.103:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.106:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.106:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.107:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.107:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.109:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.109:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.111:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.111:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.112:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.112:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.113:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.113:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.114:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.114:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.115:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.115:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.117:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.117:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.121:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.121:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.122:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.122:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.124:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.124:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.125:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.125:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.126:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.126:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.127:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.127:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.128:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.128:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.129:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.129:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.130:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.130:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.131:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.131:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.132:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.132:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.133:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.133:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.134:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.134:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.135:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.135:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.136:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.136:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.137:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.137:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.139:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.139:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.140:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.140:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.141:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.141:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.142:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.142:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.143:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.143:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.144:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.144:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.145:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.145:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.146:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.146:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.147:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.147:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.148:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.148:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.149:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.149:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.150:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.150:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.151:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.151:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.152:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.152:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.153:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.153:*:*:*:*:*:*:*
  • cpe:2.3:a:sscms:siteserver_cms:5.0.154:*:*:*:*:*:*:*
    cpe:2.3:a:sscms:siteserver_cms:5.0.154:*:*:*:*:*:*:*

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