Junos OS: EX4300: Stateless firewall policer fails to discard traffic (Juniper Networks Junos OS)

CVE-2021-0243
MEDIUM 4.7

At a glance

Source
NVD
EPSS
EPSS 0.38 % · percentile 32 ()
State
PUBLISHED
Published
Updated
Assigner
juniper
NVD status
Modified

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.

Weaknesses (CWE)

  • CWE-241 — Improper Handling of Unexpected Data Type

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 4.7CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Ljuniper
CVSS 3.1MEDIUM 4.7CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:LNVD · sirt@juniper.net (Secondary)
CVSS 2.0LOW 3.3AV:A/AC:L/Au:N/C:N/I:N/A:PNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Juniper Networks · Junos OSaffected unspecified < 17.3R3-S10 ; affected 17.4 < 17.4R3-S3 ; affected 18.1 < 18.1R3-S11 ; affected 18.2 < 18.2R3-S6 ; affected 18.3 < 18.3R3-S4 ; affected 18.4 < 18.4R3-S6

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD