CVE-2021-0246 Vulnerability Analysis & Exploit Details

CVE-2021-0246
Vulnerability Scoring

7.3
/10
Very High Risk

Highly exploitable, CVE-2021-0246 poses a critical security risk that could lead to severe breaches.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Local
    Vulnerability requires local system 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-2021-0246 Details

Status: Modified

Last updated: 🕠 21 Nov 2024, 05:42 UTC
Originally published on: 🕗 22 Apr 2021, 20:15 UTC

Time between publication and last update: 1308 days

CVSS Release: version 3

CVSS3 Source

sirt@juniper.net

CVSS3 Type

Secondary

CVSS3 Vector

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

CVE-2021-0246 Vulnerability Summary

CVE-2021-0246: On SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3, devices using tenant services on Juniper Networks Junos OS, due to incorrect default permissions assigned to tenant system administrators a tenant system administrator may inadvertently send their network traffic to one or more tenants while concurrently modifying the overall device system traffic management, affecting all tenants and the service provider. Further, a tenant may inadvertently receive traffic from another tenant. This issue affects: Juniper Networks Junos OS 18.3 version 18.3R1 and later versions on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2; 18.3 versions prior to 18.3R3 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2; 18.4 versions prior to 18.4R2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3; 19.1 versions prior to 19.1R2 on SRX1500, SRX4100, SRX4200, SRX4600, SRX5000 Series with SPC2/SPC3. This issue does not affect: Juniper Networks Junos OS versions prior to 18.3R1.

Assessing the Risk of CVE-2021-0246

Access Complexity Graph

The exploitability of CVE-2021-0246 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-2021-0246

The exploitability of CVE-2021-0246 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-2021-0246, 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-2021-0246, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: Low
    CVE-2021-0246 could lead to minor leaks of non-critical information without major privacy breaches.
  • Integrity: High
    CVE-2021-0246 could allow unauthorized modifications to data, potentially affecting system reliability and trust.
  • Availability: Low
    CVE-2021-0246 may slightly degrade system performance without fully affecting service availability.

Exploit Prediction Scoring System (EPSS)

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

EPSS Score: 0.044% (probability of exploit)

EPSS Percentile: 15.33% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 84.67% of others.

CVE-2021-0246 References

External References

CWE Common Weakness Enumeration

CWE-276

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.
  • Directory Indexing CAPEC-127 An adversary crafts a request to a target that results in the target listing/indexing the content of a directory as output. One common method of triggering directory contents as output is to construct a request containing a path that terminates in a directory name rather than a file name since many applications are configured to provide a list of the directory's contents when such a request is received. An adversary can use this to explore the directory tree on a target as well as learn the names of files. This can often end up revealing test files, backup files, temporary files, hidden files, configuration files, user accounts, script contents, as well as naming conventions, all of which can be used by an attacker to mount additional attacks.
  • Web Server Logs Tampering CAPEC-81 Web Logs Tampering attacks involve an attacker injecting, deleting or otherwise tampering with the contents of web logs typically for the purposes of masking other malicious behavior. Additionally, writing malicious data to log files may target jobs, filters, reports, and other agents that process the logs in an asynchronous attack pattern. This pattern of attack is similar to "Log Injection-Tampering-Forging" except that in this case, the attack is targeting the logs of the web server and not the application.

Vulnerable Configurations

  • cpe:2.3:o:juniper:junos:18.3:-:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:-:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r1:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r1:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r1-s1:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r1-s1:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r1-s2:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r1-s2:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r1-s3:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r1-s3:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r1-s4:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r1-s4:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r1-s5:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r1-s5:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r1-s6:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r1-s6:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r2:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r2:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r2-s1:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r2-s1:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r2-s2:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r2-s2:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r2-s3:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r2-s3:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.3:r2-s4:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.3:r2-s4:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:-:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:-:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:r1:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:r1:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:r1-s1:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:r1-s1:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:r1-s2:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:r1-s2:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:r1-s3:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:r1-s3:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:r1-s4:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:r1-s4:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:r1-s5:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:r1-s5:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:r1-s6:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:r1-s6:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:18.4:r1-s7:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:18.4:r1-s7:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:19.1:-:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:19.1:-:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:19.1:r1:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:19.1:r1:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:19.1:r1-s1:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:19.1:r1-s1:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:19.1:r1-s2:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:19.1:r1-s2:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:19.1:r1-s3:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:19.1:r1-s3:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:19.1:r1-s4:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:19.1:r1-s4:*:*:*:*:*:*
  • cpe:2.3:o:juniper:junos:19.1:r1-s5:*:*:*:*:*:*
    cpe:2.3:o:juniper:junos:19.1:r1-s5:*:*:*:*:*:*
  • cpe:2.3:h:juniper:srx1500:-:*:*:*:*:*:*:*
    cpe:2.3:h:juniper:srx1500:-:*:*:*:*:*:*:*
  • cpe:2.3:h:juniper:srx4100:-:*:*:*:*:*:*:*
    cpe:2.3:h:juniper:srx4100:-:*:*:*:*:*:*:*
  • cpe:2.3:h:juniper:srx4200:-:*:*:*:*:*:*:*
    cpe:2.3:h:juniper:srx4200:-:*:*:*:*:*:*:*
  • cpe:2.3:h:juniper:srx4600:-:*:*:*:*:*:*:*
    cpe:2.3:h:juniper:srx4600:-:*:*:*:*:*:*:*
  • cpe:2.3:h:juniper:srx5400:-:*:*:*:*:*:*:*
    cpe:2.3:h:juniper:srx5400:-:*:*:*:*:*:*:*
  • cpe:2.3:h:juniper:srx5600:-:*:*:*:*:*:*:*
    cpe:2.3:h:juniper:srx5600:-:*:*:*:*:*:*:*
  • cpe:2.3:h:juniper:srx5800:-:*:*:*:*:*:*:*
    cpe:2.3:h:juniper:srx5800:-:*:*:*:*:*:*:*

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