Junos OS and Junos OS Evolved: Due to a race condition the rpd process can crash upon receipt of a BGP update message containing flow spec route
A Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in Routing Protocol Daemon (rpd) of Juniper Networks Junos OS, Junos OS Evolved allows a network-based unauthenticated attacker to cause a Denial of Service (DoS). When a BGP flow route with redirect IP extended community is received, and the reachability to the next-hop of the corresponding redirect IP is flapping, the rpd process might crash. Whether the crash occurs depends on the timing of the internally processing of these two events and is outside the attackers control. Please note that this issue also affects Route-Reflectors unless 'routing-options flow firewall-install-disable' is configured. This issue affects: Juniper Networks Junos OS: 18.4 versions prior to 18.4R2-S10, 18.4R3-S10; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S8, 19.2R3-S4; 19.4 versions prior to 19.4R3-S8; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S2; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-EVO; 21.1-EVO versions prior to 21.1R2-EVO. This issue does not affect Juniper Networks Junos OS versions prior to 18.4R1.
Noroxi analysis
No Noroxi analysis for this record yet
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We use this product, ask for help- Published
- Oct 17, 2022
- Updated
- Jun 17, 2026
- EPSS
- 0.5% · 39th percentile
- CWE
- CWE-367
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Report tools
Action score
23
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.9
- CNA · juniper
- 5.9
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| juniper | junos | cpe:2.3:o:juniper:junos |
| juniper | junos os evolved | cpe:2.3:o:juniper:junos_os_evolved |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- juniper junosbefore 18.4
- juniper junos18.4
- juniper junos19.1
- juniper junos19.4
- juniper junos20.2
- juniper junos20.3
- juniper junos20.4
- juniper junos21.1
- juniper junos os evolvedbefore 20.4
- juniper junos os evolved20.4
- juniper junos os evolved21.1
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
- unspecified and later · before 18.4R1not affected
- 18.4 and later · before 18.4R2-S10, 18.4R3-S10affected
- 19.1 and later · before 19.1R3-S7affected
- 19.2 and later · before 19.2R1-S8, 19.2R3-S4affected
- 19.4 and later · before 19.4R3-S8affected
- 20.2 and later · before 20.2R3-S3affected
- 20.3 and later · before 20.3R3-S2affected
- 20.4 and later · before 20.4R3affected
- 21.1 and later · before 21.1R2affected
Juniper Networks Junos OS Evolved
- unspecified and later · before 20.4R2-EVOaffected
- 21.1-EVO and later · before 21.1R2-EVOaffected
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.
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.
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.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race ConditionCVSS vector
CVSS:3.1/AV:N/AC:H/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.
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.