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An Improper Check or Handling of Exceptional Conditions...

Moderate severity Unreviewed Published Jul 14, 2023 to the GitHub Advisory Database • Updated Apr 4, 2024

Package

No package listed— Suggest a package

Affected versions

Unknown

Patched versions

Unknown

Description

An Improper Check or Handling of Exceptional Conditions vulnerability in the Layer-2 control protocols daemon (l2cpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause a Denial of Service (DoS).

When a malformed LLDP packet is received, l2cpd will crash and restart. The impact of the l2cpd crash is reinitialization of STP protocols (RSTP, MSTP or VSTP), and MVRP and ERP. Also, if any services depend on LLDP state (like PoE or VoIP device recognition), then these will also be affected. Continued receipt of such packets will lead to a sustained Denial of Service.

This issue affects:
Juniper Networks Junos OS
21.4 versions prior to 21.4R3-S3;
22.1 versions prior to 22.1R3-S3;
22.2 versions prior to 22.2R2-S1, 22.2R3;
22.3 versions prior to 22.3R2.

Juniper Networks Junos OS Evolved
21.4-EVO versions prior to 21.4R3-S2-EVO;
22.1-EVO versions prior to 22.1R3-S3-EVO;
22.2-EVO versions prior to 22.2R2-S1-EVO, 22.2R3-EVO;
22.3-EVO versions prior to 22.3R2-EVO.

References

Published by the National Vulnerability Database Jul 14, 2023
Published to the GitHub Advisory Database Jul 14, 2023
Last updated Apr 4, 2024

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.044%
(14th percentile)

Weaknesses

CVE ID

CVE-2023-36849

GHSA ID

GHSA-px74-prrr-j3jp

Source code

No known source code

Dependabot alerts are not supported on this advisory because it does not have a package from a supported ecosystem with an affected and fixed version.

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