Junos OS: SRX Series: flowd process crash due to processing of specific transit IP packets
Noroxi assessment
Priority: Monitor (action score 30/100)
- 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: 1.3% (FIRST EPSS); higher than 70.9% of all records.
- 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.
- Fixed version: Juniper Networks Junos OS 18.2R3.
Low priority for now. Upgrade to Juniper Networks Junos OS 18.2R3 or later.
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
The flowd process, responsible for forwarding traffic in SRX Series services gateways, may crash and restart when processing specific transit IP packets through an IPSec tunnel. Continued processing of these packets may result in an extended Denial of Service (DoS) condition. This issue only occurs when IPSec tunnels are configured. Systems without IPSec tunnel configurations are not vulnerable to this issue. This issue affects Juniper Networks Junos OS: 15.1X49 versions prior to 15.1X49-D171, 15.1X49-D180 on SRX Series; 18.2 versions 18.2R2-S1 and later, prior to 18.2R3 on SRX Series; 18.4 versions prior to 18.4R2 on SRX Series.
- Published
- Oct 9, 2019
- Updated
- Jun 16, 2026
- EPSS
- 1.3% · 71th percentile
- CWE
- CWE-755
Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.3%
CNA vs NVD score
- NVD
- 7.5
- CNA · juniper
- 7.5
- agree
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
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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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.
We use this product, ask for helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| juniper | junos | cpe:2.3:o:juniper:junos |
| juniper | csrx | cpe:2.3:h:juniper:csrx |
| juniper | srx100 | cpe:2.3:h:juniper:srx100 |
| juniper | srx110 | cpe:2.3:h:juniper:srx110 |
| juniper | srx1400 | cpe:2.3:h:juniper:srx1400 |
| juniper | srx1500 | cpe:2.3:h:juniper:srx1500 |
| juniper | srx210 | cpe:2.3:h:juniper:srx210 |
| juniper | srx220 | cpe:2.3:h:juniper:srx220 |
| juniper | srx240 | cpe:2.3:h:juniper:srx240 |
| juniper | srx300 | cpe:2.3:h:juniper:srx300 |
| juniper | srx320 | cpe:2.3:h:juniper:srx320 |
| juniper | srx340 | cpe:2.3:h:juniper:srx340 |
and 13 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- juniper junos15.1x49
- juniper junos18.2
- juniper junos18.4
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
- 15.1X49 and later · before 15.1X49-D171, 15.1X49-D180affected
- 18.2R2-S1 and later · before 18.2*affectedfixed in 18.2R3
- 18.4 and later · before 18.4R2affected
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 | 18.2R3 | 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.
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
- 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
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-755 · Improper Handling of Exceptional ConditionsCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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✗ → ✓
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References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.