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CVE Record

CVE-2023-1829: Use-after-free in tcindex (traffic control index filter) in the Linux Kernel

A use-after-free vulnerability in the Linux Kernel traffic control index filter (tcindex) can be exploited to achieve local privilege escalation. The tcindex_delete function which does not properly deactivate filters in case of a perfect hashes while deleting the underlying structure which can later lead to double freeing the structure. A local attacker user can use this vulnerability to elevate its privileges to root. We recommend upgrading past commit 8c710f75256bb3cf05ac7b1672c82b92c43f3d28 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/ .

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A flaw in the Linux kernel’s tcindex traffic-control filter can let an already authenticated local user gain root privileges. Successful exploitation could expose all data, permit system changes, and disrupt availability. It is serious for shared Linux hosts and systems granting access to untrusted users.

Executive priority

Treat as a high-priority privilege-escalation issue, especially on shared Linux infrastructure. Patch exposed systems promptly through supported vendor packages. Internet-facing status alone is not the deciding factor because exploitation requires local access; account access and workload isolation should drive prioritization.

Technical view

CVE-2023-1829 is a CWE-416 use-after-free in tcindex deletion. Improper filter deactivation with perfect hashes can lead to a double free and local privilege escalation. CVSS 3.1 is 7.8: local access, low complexity, low privileges, no user interaction, and high confidentiality, integrity, and availability impact.

Likely exposure

Exposure requires a Linux kernel containing the vulnerable tcindex implementation and a local attacker with low privileges. Shared servers, multi-user systems, and hosts permitting untrusted local accounts deserve priority. The supplied version list is ambiguous, so determine exposure through vendor package advisories and fix-backport status rather than version matching alone.

Exploitation context

The supplied sources describe local privilege escalation to root but provide no evidence of active exploitation. The CVE is not identified as KEV in the bundle. This does not prove exploitation is absent; it means active exploitation should not be claimed from the available evidence.

Researcher notes

The vulnerable path is tcindex filter deletion involving perfect-hash handling, where filters may remain active after underlying structures are freed. The source recommends upgrading past the referenced commit. Exact affected release boundaries and downstream backport coverage are not established clearly in the bundle, so package-level vendor confirmation is necessary.

Mitigation direction

  • Upgrade to a vendor kernel containing or superseding commit 8c710f75256bb3cf05ac7b1672c82b92c43f3d28.
  • Check distribution and appliance vendor advisories for patched package versions and backports.
  • Prioritize shared or multi-user Linux systems where untrusted users have local access.
  • Restrict unnecessary local accounts and privileges while remediation is pending.

Validation and detection

  • Inventory running kernel and installed kernel package versions across Linux systems.
  • Confirm with vendors whether each kernel includes the referenced fix or an equivalent backport.
  • Identify systems using or exposing the tcindex traffic-control filter.
  • Review which untrusted or low-privileged users can access potentially affected hosts.
  • After updating, verify the patched kernel is running following any required reboot.
Prepared
Confidence
medium
Sources
5

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-416: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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description · low confidence lookup

Privilege behavior lookup

The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2023-1829 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
2ADP providers
6Source links

SSVC decision data

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

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
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Google

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2023-1829Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux Kernelkernel, 3.8.0, 4.15.0, 4.20.0, 5.5.0, 5.11.0, 5.16.0, 6.2.0, 6.3.0, 8c710f75256bb3cf05ac7b1672c82b92c43f3d28unaffected
Weakness

CWE details

CWE-416

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

CWE-416 · source CWE mapping

Use After Free

Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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