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CVE Record

CVE-2024-36971: net: fix __dst_negative_advice() race

In the Linux kernel, the following vulnerability has been resolved: net: fix __dst_negative_advice() race __dst_negative_advice() does not enforce proper RCU rules when sk->dst_cache must be cleared, leading to possible UAF. RCU rules are that we must first clear sk->sk_dst_cache, then call dst_release(old_dst). Note that sk_dst_reset(sk) is implementing this protocol correctly, while __dst_negative_advice() uses the wrong order. Given that ip6_negative_advice() has special logic against RTF_CACHE, this means each of the three ->negative_advice() existing methods must perform the sk_dst_reset() themselves. Note the check against NULL dst is centralized in __dst_negative_advice(), there is no need to duplicate it in various callbacks. Many thanks to Clement Lecigne for tracking this issue. This old bug became visible after the blamed commit, using UDP sockets.

HighCVSS 7.8Known exploitedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A Linux kernel networking race can leave the kernel using freed memory. A locally authenticated, low-privileged attacker may potentially compromise confidentiality, integrity, and availability. CISA lists CVE-2024-36971 as known exploited, making remediation urgent despite the source bundle providing no details about observed attacks.

Executive priority

Treat as a high-priority kernel update because exploitation is known and successful abuse could affect the entire host. Accelerate remediation on systems permitting local users, containers, or other untrusted workloads. Use vendor-specific build guidance because the supplied affected-version listing is ambiguous.

Technical view

__dst_negative_advice() released a cached network destination before clearing sk_dst_cache, violating required RCU ordering and enabling a use-after-free. The issue became observable with UDP sockets. The supplied CVSS 3.1 score is 7.8 with local, low-complexity, low-privilege exploitation and no user interaction.

Likely exposure

Exposure is most likely on Linux systems running kernel builds that lack the stable correction, particularly where untrusted or lower-privileged users can execute local workloads. The supplied version data is not sufficiently clear for reliable range-based determination; assess vendor kernel builds and backports individually.

Exploitation context

CISA KEV status supports active exploitation in the wild. However, the supplied sources do not describe exploitation scale, targeted sectors, attack chains, or whether public exploit code exists. The CVSS vector indicates an attacker first requires low-privileged local access.

Researcher notes

CWE-416 applies. The corrective design clears sk_dst_cache before releasing old_dst, consistent with sk_dst_reset(). Each negative_advice callback must perform the reset because IPv6 has RTF_CACHE-specific handling. The bundle supplies multiple stable commits but does not map each commit clearly to every affected kernel build.

Mitigation direction

  • Upgrade to a vendor-supported kernel containing the CVE-2024-36971 correction or an equivalent backport.
  • Consult the Linux distribution or appliance vendor for exact fixed build identifiers.
  • Prioritize shared, multi-user, and externally reachable workload hosts where local code execution is possible.
  • Restrict unnecessary local accounts and untrusted workload execution until patching is complete.
  • Reboot into the corrected kernel and remove vulnerable kernels from normal boot options.

Validation and detection

  • Record each system's running kernel release, build, distribution, and architecture.
  • Compare builds against vendor advisories and documented backports, not upstream version numbers alone.
  • Confirm the running kernel contains the applicable stable fix or vendor-equivalent change.
  • Verify systems rebooted successfully into the corrected kernel after installation.
  • Review kernel crash and networking telemetry for unexplained use-after-free or UDP-related instability.
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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cve · low confidence lookup

CVE-2024-36971 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
Yes
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.

2CVSS vectors
5Timeline events
2ADP providers
11Source links

CISA KEV status

Status
Known exploited
Source
CISA-ADP
Date added
KEV reference

SSVC decision data

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

CVSS vector scores

2 official scores

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

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2024-36971Attack 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. Added to KEVCISA-ADP

    CISA Known Exploited Vulnerabilities metadata lists this CVE as known exploited.

  4. ADP timelineCISA-ADP

    CVE-2024-36971 added to CISA KEV

  5. CVE updatedCVE Program

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

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvcother:kev
  • 2024-08-07T00:00:00.000Z: CVE-2024-36971 added to CISA KEV

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxa87cb3e48ee86d29868d3f59cfb9ce1a8fa63314, a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314, a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314, a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314, a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314, a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314, a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314, a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314unaffected
LinuxLinux4.6, 0, 4.19.316, 5.4.278, 5.10.219, 5.15.161, 6.1.94, 6.6.34, 6.9.4, 6.10affected
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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