Junos OS: MX Series and EX9200 Series: If the "tcp-reset" option used in an IPv6 filter, matched packets are accepted instead of rejected
An Unsupported Feature in the UI vulnerability in Juniper Networks Junos OS on MX Series and EX9200 Series allows an unauthenticated, network-based attacker to cause partial impact to the integrity of the device. If the "tcp-reset" option is added to the "reject" action in an IPv6 filter which matches on "payload-protocol", packets are permitted instead of rejected. This happens because the payload-protocol match criteria is not supported in the kernel filter causing it to accept all packets without taking any other action. As a fix the payload-protocol match will be treated the same as a "next-header" match to avoid this filter bypass. This issue doesn't affect IPv4 firewall filters. This issue affects Juniper Networks Junos OS on MX Series and EX9200 Series: * All versions earlier than 20.4R3-S7; * 21.1 versions earlier than 21.1R3-S5; * 21.2 versions earlier than 21.2R3-S5; * 21.3 versions earlier than 21.3R3-S4; * 21.4 versions earlier than 21.4R3-S4; * 22.1 versions earlier than 22.1R3-S2; * 22.2 versions earlier than 22.2R3-S2; * 22.3 versions earlier than 22.3R2-S2, 22.3R3; * 22.4 versions earlier than 22.4R1-S2, 22.4R2-S2, 22.4R3.
- Published
- Jan 11, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.3% · 22th percentile
- CWE
- CWE-447
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.3
- CNA · juniper
- 5.3
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| juniper | junos | cpe:2.3:o:juniper:junos |
| juniper | ex9200 | cpe:2.3:h:juniper:ex9200 |
| juniper | ex9204 | cpe:2.3:h:juniper:ex9204 |
| juniper | ex9208 | cpe:2.3:h:juniper:ex9208 |
| juniper | mx10 | cpe:2.3:h:juniper:mx10 |
| juniper | mx10000 | cpe:2.3:h:juniper:mx10000 |
| juniper | mx10003 | cpe:2.3:h:juniper:mx10003 |
| juniper | mx10004 | cpe:2.3:h:juniper:mx10004 |
| juniper | mx10008 | cpe:2.3:h:juniper:mx10008 |
| juniper | mx10016 | cpe:2.3:h:juniper:mx10016 |
| juniper | mx104 | cpe:2.3:h:juniper:mx104 |
| juniper | mx150 | cpe:2.3:h:juniper:mx150 |
and 11 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- juniper junosbefore 20.4
- juniper junos20.4
- juniper junos21.1
- juniper junos21.2
- juniper junos21.3
- juniper junos21.4
- juniper junos22.1
- juniper junos22.2
- juniper junos22.3
- juniper junos22.4
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
- before 20.4R3-S7affected · semver
- 21.1 and later · before 21.1R3-S5affected · semver
- 21.2 and later · before 21.2R3-S5affected · semver
- 21.3 and later · before 21.3R3-S4affected · semver
- 21.4 and later · before 21.4R3-S4affected · semver
- 22.1 and later · before 22.1R3-S2affected · semver
- 22.2 and later · before 22.2R3-S2affected · semver
- 22.3 and later · before 22.3R2-S2, 22.3R3affected · semver
- 22.4 and later · before 22.4R1-S2, 22.4R2-S2, 22.4R3affected · semver
Same product
juniper: all recordsOther 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 variableKEV98Now
- CVE-2023-36846Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV79This week
- CVE-2023-36844Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variablesKEV78This week
- CVE-2023-36847Junos OS: EX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV76This week
- CVE-2020-1631Out of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) servicesKEV70This week
- CVE-2025-21590Junos OS: An local attacker with shell access can execute arbitrary codeKEV57Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Juniper Networks Junos OS | 20.4R3-S7 | Vendor (CNA) |
| Juniper Networks Junos OS | 21.1R3-S5 | Vendor (CNA) |
| Juniper Networks Junos OS | 21.2R3-S5 | Vendor (CNA) |
| Juniper Networks Junos OS | 21.3R3-S4 | Vendor (CNA) |
| Juniper Networks Junos OS | 21.4R3-S4 | Vendor (CNA) |
| Juniper Networks Junos OS | 22.1R3-S2 | Vendor (CNA) |
| Juniper Networks Junos OS | 22.2R3-S2 | Vendor (CNA) |
| Juniper Networks Junos OS | 22.3R2-S2, 22.3R3 | Vendor (CNA) |
| Juniper Networks Junos OS | 22.4R1-S2, 22.4R2-S2, 22.4R3 | Vendor (CNA) |
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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
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 researchersFinders, 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.
- CVE-2024-39533182 days apartJunos OS: QFX5000 Series and EX4600 Series: Output firewall filter is not applied if certain match criteria are used27Monitor
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
- Anyone who can reach it over the internet 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
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-447 · Unimplemented or Unsupported Feature in UICVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- supportportal.juniper.net/JSA75748
- www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Vendor advisories and official records. Exploit/PoC links are deliberately left out.