CVE-2023-36834

Junos OS: SRX 4600 and SRX 5000 Series: The receipt of specific genuine packets by SRXes configured for L2 transparency will cause a DoS

MEDIUM

6.5

CVSS Score

Published: July 14, 2023 at 05:04 PM UTC

Updated: June 17, 2026 at 06:07 AM UTC

5 products affected across 2 vendorsJunosSRX5800SRX5600

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Severity

MEDIUM6.5

Exploit prediction

EPSS 0.3%

SSVC

No known exploit

Description

An Incomplete Internal State Distinction vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on SRX 4600 and SRX 5000 Series allows an adjacent attacker to cause a Denial of Service (DoS). If an SRX is configured in L2 transparent mode the receipt of a specific genuine packet can cause a single Packet Processing Engines (PPE) component of the PFE to run into a loop, which in turn will render the PPE unavailable. Each packet will cause one PPE to get into a loop, leading to a gradual performance degradation until all PPEs are unavailable and all traffic processing stops. To recover the affected FPC need to be restarted. This issue affects Juniper Networks Junos OS on SRX 4600 and SRX 5000 Series: 20.1 version 20.1R1 and later versions; 20.2 versions prior to 20.2R3-S7; 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S7; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S3; 21.3 versions prior to 21.3R3-S3; 21.4 versions prior to 21.4R3-S1; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R1-S1, 22.3R2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

20.1 ≤ v < 20.1*20.2 ≤ v < 20.2R3-S720.3 ≤ v < 20.3*20.4 ≤ v < 20.4R3-S721.1 ≤ v < 21.1R3-S521.2 ≤ v < 21.2R3-S321.3 ≤ v < 21.3R3-S321.4 ≤ v < 21.4R3-S122.1 ≤ v < 22.1R322.2 ≤ v < 22.2R222.3 ≤ v < 22.3R1-S1, 22.3R220.1 20.1 r1 20.1 r1-s1 20.1 r1-s2 20.1 r1-s3 20.1 r1-s4 20.1 r2 20.1 r2-s1 20.1 r2-s2 20.1 r3 20.1 r3-s1 20.1 r3-s2 20.1 r3-s3 20.1 r3-s4 20.1 r3-s5 20.2 20.2 r1 20.2 r1-s1 20.2 r1-s2 20.2 r1-s3 20.2 r2 20.2 r2-s1 20.2 r2-s2 20.2 r2-s3 20.2 r3 20.2 r3-s1 20.2 r3-s2 20.2 r3-s3 20.2 r3-s4 20.2 r3-s5 20.2 r3-s6 20.3 20.3 r1 20.3 r1-s1 20.3 r1-s2 20.3 r2 20.3 r2-s1 20.3 r3 20.3 r3-s1 20.3 r3-s2 20.3 r3-s3 20.3 r3-s4 20.3 r3-s5 20.3 r3-s6 20.4 20.4 r1 20.4 r1-s1 20.4 r2 20.4 r2-s1 20.4 r2-s2 20.4 r3 20.4 r3-s1 20.4 r3-s2 20.4 r3-s3 20.4 r3-s4 20.4 r3-s5 20.4 r3-s6 21.1 21.1 r1 21.1 r1-s1 21.1 r2 21.1 r2-s1 21.1 r2-s2 21.1 r3 21.1 r3-s1 21.1 r3-s2 21.1 r3-s3 21.1 r3-s4 21.2 21.2 r1 21.2 r1-s1 21.2 r1-s2 21.2 r2 21.2 r2-s1 21.2 r2-s2 21.2 r3 21.2 r3-s1 21.2 r3-s2 21.3 21.3 r1 21.3 r1-s1 21.3 r1-s2 21.3 r2 21.3 r2-s1 21.3 r2-s2 21.3 r3 21.3 r3-s1 21.3 r3-s2 21.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 21.4 r3 22.1 22.2 22.3

Affected range stops below 20.1*, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.2R3-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.3*, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.4R3-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.1R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.2R3-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.3R3-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.1R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R1-S1, 22.3R2, so it looks safe — our inference, not a vendor statement

juniper-srx4600 (environment) · juniper-srx5400 (environment) · juniper-srx5600 (environment) · juniper-srx5800 (environment)

Srx4600 · Juniperdevice

80%

All versions

Srx5400 · Juniperdevice

80%

All versions

SRX5600 · Juniperdevice

80%

All versions

SRX5800 · Juniperdevice

80%

All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://supportportal.juniper.net/JSA71641

References (1)

Vendor Advisory

Source: [email protected]

https://supportportal.juniper.net/JSA71641

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMjuniper

Attack Vector: ADJACENT_NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-372

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