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NVD / CVE Program· CNA juniper

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

Noroxi assessment

Priority: Monitor (action score 26/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.30% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 6.5 · v3.1—No exploit No fix recorded
Published
Jul 14, 2023
Updated
Jun 17, 2026
EPSS
0.3% · 23th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · juniper
6.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-36834

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
juniperjunos
junipersrx4600
junipersrx5400
junipersrx5600
junipersrx5800

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • juniper junos20.1
  • juniper junos20.2
  • juniper junos20.3
  • juniper junos20.4
  • juniper junos21.1
  • juniper junos21.2
  • juniper junos21.3
  • juniper junos21.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (juniper). Independent of NVD's CPE analysis and usually ahead of it.

  • Juniper Networks Junos OS

    • 20.1 and later · before 20.1*affected
    • 20.2 and later · before 20.2R3-S7affected
    • 20.3 and later · before 20.3*affected
    • 20.4 and later · before 20.4R3-S7affected
    • 21.1 and later · before 21.1R3-S5affected
    • 21.2 and later · before 21.2R3-S3affected
    • 21.3 and later · before 21.3R3-S3affected
    • 21.4 and later · before 21.4R3-S1affected
    • 22.1 and later · before 22.1R3affected
    • 22.2 and later · before 22.2R2affected

Same product

juniper: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-36845Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to control an important environment variableKEV
    98Now
  • CVE-2023-36846Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV
    79This week
  • CVE-2023-36844Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variablesKEV
    78This week

Published before and after this one in the same product

  • ← EarlierCVE-2023-28985Jul 14, 2023 · SRX Series and MX Series: An FPC core is observed when IDP is enabled on the device and a specific malformed SSL packet is received
    30Monitor
  • ← EarlierCVE-2023-36838Jul 14, 2023 · Junos OS: SRX Series: A flowd core occurs when running a low privileged CLI command
    22Monitor
  • Later →CVE-2023-36835Jul 14, 2023 · Junos OS: QFX10000 Series: All traffic will be dropped after a specific valid IP packet has been received which needs to be routed over a VXLAN tunnel
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-372 · Incomplete Internal State Distinction

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records