4.7
MEDIUM
CVE-2021-0243
Juniper Networks Junos OS EX4300 Junos OS Firewall Policer Denial of Service
Description

Improper Handling of Unexpected Data in the firewall policer of Juniper Networks Junos OS on EX4300 switches allows matching traffic to exceed set policer limits, possibly leading to a limited Denial of Service (DoS) condition. When the firewall policer discard action fails on a Layer 2 port, it will allow traffic to pass even though it exceeds set policer limits. Traffic will not get discarded, and will be forwarded even though a policer discard action is configured. When the issue occurs, traffic is not discarded as desired, which can be observed by comparing the Input bytes with the Output bytes using the following command: user@junos> monitor interface traffic Interface Link Input bytes (bps) Output bytes (bps) ge-0/0/0 Up 37425422 (82616) 37425354 (82616) <<<< egress ge-0/0/1 Up 37425898 (82616) 37425354 (82616) <<<< ingress The expected output, with input and output counters differing, is shown below: Interface Link Input bytes (bps) Output bytes (bps) ge-0/0/0 Up 342420570 (54600) 342422760 (54600) <<<< egress ge-0/0/1 Up 517672120 (84000) 342420570 (54600) <<<< ingress This issue only affects IPv4 policing. IPv6 traffic and firewall policing actions are not affected by this issue. This issue affects Juniper Networks Junos OS on the EX4300: All versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R3-S6; 19.1 versions prior to 19.1R3-S3; 19.2 versions prior to 19.2R3-S1; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R2.

INFO

Published Date :

April 22, 2021, 8:15 p.m.

Last Modified :

Nov. 21, 2024, 5:42 a.m.

Source :

[email protected]

Remotely Exploitable :

No

Impact Score :

1.4

Exploitability Score :

2.8
Affected Products

The following products are affected by CVE-2021-0243 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Juniper junos
2 Juniper ex4300
: Total Affected Vendor : 1 | Products : 2
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-0243.

URL Resource
https://kb.juniper.net/JSA11136 Vendor Advisory
https://kb.juniper.net/JSA11136 Vendor Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-0243 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-0243 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://kb.juniper.net/JSA11136
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Initial Analysis by [email protected]

    Apr. 27, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:A/AC:L/Au:N/C:N/I:N/A:P)
    Changed Reference Type https://kb.juniper.net/JSA11136 No Types Assigned https://kb.juniper.net/JSA11136 Vendor Advisory
    Added CWE NIST NVD-CWE-Other
    Added CPE Configuration AND OR *cpe:2.3:o:juniper:junos:17.3:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r1-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r2-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r2-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r2-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3:-:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s6:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s7:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s8:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.3:r3-s9:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r1-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r1-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r1-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r1-s6:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r1-s7:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s10:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s11:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s12:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s6:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s7:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s8:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r2-s9:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:17.4:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r2-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s10:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s6:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s7:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s8:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.1:r3-s9:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r1:-:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r1-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r1-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r1-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r2-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r2-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r2-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r2-s6:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r2-s7:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r3-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r3-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.2:r3-s5:*:*:*:*:*:* *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-s1:*:*:*:*:*:* *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-s4:*:*:*:*:*:* *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:r2:*:*:*:*:*:* *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-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.3:r2-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.3:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.3:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.3:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.3:r3-s3:*:*:*:*:*:* *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-s1:*:*:*:*:*:* *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-s4:*:*:*:*:*:* *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-s7:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r2-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r2-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r2-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r2-s6:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r3-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r3-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:18.4:r3-s5:*:*:*:*:*:* *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-s1:*:*:*:*:*:* *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-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.1:r1-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.1:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.1:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.1:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.1:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.1:r3-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r1-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r1-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r1-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.2:r3-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:-:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r2-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r2-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r2-s5:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.3:r3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.4:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.4:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.4:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.4:r2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.4:r2-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:19.4:r2-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.1:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.1:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.1:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.1:r1-s3:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.1:r1-s4:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.2:r1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.2:r1-s1:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.2:r1-s2:*:*:*:*:*:* *cpe:2.3:o:juniper:junos:20.2:r1-s3:*:*:*:*:*:* OR cpe:2.3:h:juniper:ex4300:-:*:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-0243 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-0243 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.06 }} 0.00%

score

0.27147

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
: