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JunosOperating system · Juniper

CVE-2022-22155

MEDIUM · 6.5 CVSS v3.1 Published 2022-01-19
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An Uncontrolled Resource Consumption vulnerability in the handling of IPv6 neighbor state change events in Juniper Networks Junos OS allows an adjacent attacker to cause a memory leak in the Flexible PIC Concentrator (FPC) of an ACX5448 router. The continuous flapping of an IPv6 neighbor with specific timing will cause the FPC to run out of resources, leading to a Denial of Service (DoS) condition. Once the condition occurs, further packet processing will be impacted, creating a sustained Denial of Service (DoS) condition, requiring a manual PFE restart to restore service. The following error messages will be seen after the FPC resources have been exhausted: fpc0 DNX_NH::dnx_nh_tag_ipv4_hw_install(),3135: dnx_nh_tag_ipv4_hw_install: BCM L3 Egress create object failed for NH 602 (-14:No resources for operation), BCM NH Params: unit:0 Port:41, L3_INTF:0 Flags: 0x40 fpc0 DNX_NH::dnx_nh_tag_ipv4_hw_install(),3135: dnx_nh_tag_ipv4_hw_install: BCM L3 Egress create object failed for NH 602 (-14:No resources for operation), BCM NH Params: unit:0 Port:41, L3_INTF:0 Flags: 0x40 fpc0 DNX_NH::dnx_nh_tag_ipv4_hw_install(),3135: dnx_nh_tag_ipv4_hw_install: BCM L3 Egress create object failed for NH 602 (-14:No resources for operation), BCM NH Params: unit:0 Port:41, L3_INTF:0 Flags: 0x40 fpc0 DNX_NH::dnx_nh_tag_ipv4_hw_install(),3135: dnx_nh_tag_ipv4_hw_install: BCM L3 Egress create object failed for NH 602 (-14:No resources for operation), BCM NH Params: unit:0 Port:41, L3_INTF:0 Flags: 0x40 This issue only affects the ACX5448 router. No other products or platforms are affected by this vulnerability. This issue affects Juniper Networks Junos OS on ACX5448: 18.4 versions prior to 18.4R3-S10; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R1-S8, 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S3, 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S1, 20.2R2.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

An uncontrolled resource consumption vulnerability in Junos OS ACX5448 routers allows an adjacent attacker to cause a memory leak in the Flexible PIC Concentrator (FPC) by continuously flapping IPv6 neighbor state with specific timing. This exhausts FPC resources, causing BCM L3 Egress object creation failures and preventing further packet processing, resulting in a sustained DoS condition requiring manual PFE restart.

MitigationApply the relevant Junos OS software update (18.4R3-S10, 19.1R3-S5, 19.2R1-S8/19.2R3-S2, 19.3R2-S6/19.3R3-S2, 19.4R1-S3/19.4R2-S2/19.4R3, 20.1R2, or 20.2R1-S1/20.2R2 or later) to the ACX5448. If patching is not immediately possible, monitor for the error messages and plan for maintenance window to restart PFE if DoS occurs.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
JunosOperating system
Affected:= 18.4= 19.1= 19.2= 19.3= 19.4= 20.1= 20.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device model is ACX5448
    Run 'show chassis hardware' or 'show system information' and verify the model number in the output is ACX5448
    Affected if Device is not an ACX5448 router - this vulnerability only affects ACX5448 platforms
  2. Check installed Junos OS version
    Run 'show version' and note the exact Junos version (e.g., 18.4R1-S1, 19.2R3, etc.)
    Affected if Version matches or falls within these ranges: 18.4 (any release), 19.1 (any release), 19.2 (any release), 19.3 (any release), 19.4 (any release), 20.1 (any release), 20.2 (any release)
  3. Verify IPv6 is enabled on the device
    Run 'show ipv6 neighbors' or check interface configuration with 'show configuration protocols ipv6'
    Affected if IPv6 is enabled and active - the exploit requires IPv6 neighbor state manipulation to trigger the memory leak
  4. Monitor for BCM L3 Egress object errors
    Run 'show log messages' and search for 'BCM L3 Egress' or 'object creation failed' error messages
    Affected if Error messages indicate BCM L3 Egress object creation failures, suggesting the memory leak has been triggered
  5. Check FPC resource status
    Run 'show chassis fpc' or 'show pfe statistics traffic' to inspect FPC memory and packet processing statistics
    Affected if FPC shows high memory usage, resource exhaustion, or failure to process packets indicating the DoS condition is active

Device is affected if it is an ACX5448 router running any Junos OS version in the 18.4 through 20.2 range with IPv6 enabled, and either error messages or FPC resource exhaustion are observed.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the relevant Junos OS software update (18.4R3-S10, 19.1R3-S5, 19.2R1-S8/19.2R3-S2, 19.3R2-S6/19.3R3-S2, 19.4R1-S3/19.4R2-S2/19.4R3, 20.1R2, or 20.2R1-S1/20.2R2 or later) to the ACX5448. If patching is not immediately possible, monitor for the error messages and plan for maintenance window to restart PFE if DoS occurs.

Recommended fix High confidence

Minimum fixed versions: 18.4R3-S10, 19.1R3-S5, 19.2R3-S2 (or 19.2R1-S8), 19.3R3-S2 (or 19.3R2-S6), 19.4R3 (or 19.4R2-S2/19.4R1-S3), 20.1R2, or 20.2R2 (or 20.2R1-S1)

  1. Confirm the current Junos OS version on the ACX5448 router using 'show version'
  2. Identify the appropriate upgrade path based on the current version (18.4, 19.1, 19.2, 19.3, 19.4, 20.1, or 20.2)
  3. Download the corresponding fixed Junos OS release from the Juniper Networks support portal
  4. Plan maintenance window as upgrade will require system reboot
  5. Upload the new Junos OS image to the router's /var/tmp directory
  6. Execute 'request system software add /var/tmp/<image-name>' to install the new version
  7. After installation completes, reboot the device with 'request system reboot'
  8. Verify the upgrade was successful and the device is operational
Caveat Review Juniper release notes for any behavioral changes or configuration migration requirements between versions; test in lab environment before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Junos Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-22155 in production — separate from our analysis above.

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