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CVE Record

CVE-2022-22209: Junos OS: RIB and PFEs can get out of sync due to a memory leak caused by interface flaps or route churn

A Missing Release of Memory after Effective Lifetime vulnerability in the kernel of Juniper Networks Junos OS allows an unauthenticated network based attacker to cause a Denial of Service (DoS). On all Junos platforms, the Kernel Routing Table (KRT) queue can get stuck due to a memory leak triggered by interface flaps or route churn leading to RIB and PFEs getting out of sync. The memory leak causes RTNEXTHOP/route and next-hop memory pressure issue and the KRT queue will eventually get stuck with the error- 'ENOMEM -- Cannot allocate memory'. The out-of-sync state between RIB and FIB can be seen with the "show route" and "show route forwarding-table" command. This issue will lead to failures for adding new routes. The KRT queue status can be checked using the CLI command "show krt queue": user@host > show krt state High-priority add queue: 1 queued ADD nhtype Router index 0 (31212) error 'ENOMEM -- Cannot allocate memory' kqp '0x8ad5e40' The following messages will be observed in /var/log/messages, which indicate high memory for routes/nexthops: host rpd[16279]: RPD_RT_HWM_NOTICE: New RIB highwatermark for routes: 266 [2022-03-04 05:06:07] host rpd[16279]: RPD_KRT_Q_RETRIES: nexthop ADD: Cannot allocate memory host rpd[16279]: RPD_KRT_Q_RETRIES: nexthop ADD: Cannot allocate memory host kernel: rts_veto_net_delayed_unref_limit: Route/nexthop memory is severe pressure. User Application to perform recovery actions. O p 8 err 12, rtsm_id 0:-1, msg type 10, veto simulation: 0. host kernel: rts_veto_net_delayed_unref_limit: Memory usage of M_RTNEXTHOP type = (806321208) Max size possible for M_RTNEXTHOP type = (689432176) Current delayed unref = (0), Max delayed unref on this platform = (120000) Current delayed weight unref = (0) Max delayed weight unref on this platform = (400000) curproc = rpd. This issue affects: Juniper Networks Junos OS 21.2 versions prior to 21.2R3; 21.3 versions prior to 21.3R2-S1, 21.3R3; 21.4 versions prior to 21.4R1-S2, 21.4R2; This issue does not affect Juniper Networks Junos OS versions prior to 21.2R1.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This is a denial-of-service flaw in Juniper Junos OS. Route churn or interface flapping can trigger a kernel memory leak, causing routing state and forwarding hardware state to diverge. The business risk is loss or degradation of routing updates on affected Junos platforms, not data theft.

Executive priority

Prioritize remediation where Junos devices carry important routing functions. The issue can impair availability without credentials, and failure may appear as routing instability rather than a clean outage. Upgrade planning is the main control supported by the sources.

Technical view

CVE-2022-22209 is a CWE-401 memory leak in Junos OS kernel handling of route and next-hop state. RTNEXTHOP pressure can stall the KRT queue with allocation failures, leaving RIB and PFE/FIB state out of sync and preventing new route additions.

Likely exposure

Exposure is limited to Juniper Networks Junos OS 21.2, 21.3, and 21.4 before the fixed releases named by Juniper. Sources say all Junos platforms are affected in those trains. Junos OS versions before 21.2R1 are stated as not affected.

Exploitation context

The CVE describes unauthenticated network-based denial of service triggered by interface flaps or route churn. The bundle does not cite active exploitation, and CISA KEV status is false. Treat exploit status as unconfirmed, not active.

Researcher notes

Evidence supports a network-reachable availability impact through memory exhaustion during route or interface churn. The source bundle provides observable symptoms and affected releases, but does not provide exploit prevalence, workarounds, or affected CPE precision.

Mitigation direction

  • Inventory Junos OS devices and identify 21.2, 21.3, and 21.4 release trains.
  • Upgrade to Juniper fixed releases listed in JSA69713.
  • Prioritize devices exposed to frequent route churn or unstable interfaces.
  • Review Juniper advisory guidance before maintenance changes.
  • Monitor for route and next-hop memory pressure until upgraded.

Validation and detection

  • Confirm each Junos OS version against the affected and fixed release list.
  • Compare routing table state with forwarding table state for divergence.
  • Check KRT queue health for allocation failure symptoms.
  • Review system logs for route or next-hop memory pressure messages.
  • Verify new route additions continue succeeding during operational churn.
Prepared
Confidence
high
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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cwe · low confidence lookup

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cve · low confidence lookup

CVE-2022-22209 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2022-22209Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Juniper NetworksJunos OSunspecified, 21.2, 21.3, 21.4Listed
Weakness

CWE details

CWE-401

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-401 · source CWE mapping

Missing Release of Memory after Effective Lifetime

Missing Release of Memory after Effective Lifetime represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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