CyberSecBulletin
CVE-2023-6200NVD status: Modified

kernel: Concurrent Execution using Shared Resource with Improper Synchronization

CVE-2023-6200 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in kernel, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 2.02% chance of exploitation within 30 days, higher than 81% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux Kernel to 6.7 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
KernelkernelNot specified in the recordNot stated
Red HatRed Hat Enterprise Linux 6Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 7Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRed Hat Virtualization 4Not specified in the recordNot stated
FedoraFedoraNot specified in the recordNot stated
LinuxLinux Kernelbefore 6.7; 6.76.7

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (redhat.com)
CVSS 3.17.5HighNVD

Official description

A race condition was found in the Linux Kernel. Under certain conditions, an unauthenticated attacker from an adjacent network could send an ICMPv6 router advertisement packet, causing arbitrary code execution.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

How developers prevent this class of flaw

  • In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
  • Use thread-safe capabilities such as the data access abstraction in Spring.
  • Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

More Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities (CWE-362)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in kernel

All kernel vulnerabilities

Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities

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