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CVE Record

CVE-2022-49183: net/sched: act_ct: fix ref leak when switching zones

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: fix ref leak when switching zones When switching zones or network namespaces without doing a ct clear in between, it is now leaking a reference to the old ct entry. That's because tcf_ct_skb_nfct_cached() returns false and tcf_ct_flow_table_lookup() may simply overwrite it. The fix is to, as the ct entry is not reusable, free it already at tcf_ct_skb_nfct_cached().

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2022-49183 is a Linux kernel availability issue in traffic-control connection tracking. A local user with some privileges may trigger a reference leak when connection tracking zones or network namespaces are switched, potentially exhausting resources and disrupting service. The supplied sources do not show data theft, integrity impact, or active exploitation.

Executive priority

Treat as a moderate operational risk. It is not currently evidenced as actively exploited, but affected Linux hosts could suffer service disruption. Prioritize patching internet-facing infrastructure, shared compute, container platforms, and systems with untrusted local users.

Technical view

The bug is in net/sched act_ct. When switching zones or network namespaces without clearing conntrack state, the old conntrack entry reference can be leaked because lookup may overwrite it. The upstream fix frees the non-reusable entry earlier in tcf_ct_skb_nfct_cached(). CVSS is 5.5: local, low privilege, no user interaction, high availability impact.

Likely exposure

Exposure is most relevant on Linux systems using traffic control act_ct, conntrack zones, or network namespaces, including container or network-heavy hosts. The CVSS vector requires local access with low privileges. Exact exposure depends on distro backports and whether affected kernel code is present.

Exploitation context

The CVE bundle marks KEV as false and provides no cited evidence of active exploitation. The issue is availability-focused and local-access only under the supplied CVSS vector. Evidence is insufficient to claim remote exploitation or public weaponization.

Researcher notes

The supplied affected-version data is limited and appears tied to upstream commits and stable branches. Validate against vendor kernel advisories and backport metadata. Do not infer broader product impact beyond Linux kernel act_ct behavior documented in the CVE bundle.

Mitigation direction

  • Update to a vendor-supported kernel containing the referenced upstream stable fixes.
  • Check Linux distribution advisories for backported fixes before relying on upstream version numbers.
  • Prioritize container hosts, network appliances, and systems using tc act_ct or conntrack zones.
  • Reduce untrusted local access where kernel updates cannot be applied promptly.

Validation and detection

  • Inventory Linux kernel versions and distro patch levels across affected assets.
  • Confirm whether vendor kernels include the referenced act_ct reference leak fix.
  • Review hosts using traffic control, conntrack zones, or network namespaces.
  • After patching, verify the running kernel matches the remediated vendor build.
Prepared
Confidence
medium
Sources
7

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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2022-49183 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/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
3Timeline events
1ADP providers
6Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

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
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2022-49183Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/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

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux0fc1847359964e95e521cf2bb2b10f8e33dd0970, a95ea90deb3071c1ded77a05e91cfebc5238d908, e9408de00e5ecd0dbe91cf061c7da23711c4febb, 2f131de361f6d0eaff17db26efdb844c178432f8, 2f131de361f6d0eaff17db26efdb844c178432f8, 5.10.103, 5.15.26, 5.16.12unaffected
LinuxLinux5.17, 0, 5.10.258, 5.15.33, 5.16.19, 5.17.2, 5.18affected
Weakness

CWE details

No CWE listed

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