CyberSecBulletin
CVE-2022-2327NVD status: Modified

Linux Kernel: Double Free

Published Updated By the CyberSecBulletin desk

CVE-2022-2327 is a high-severity double free vulnerability in Linux Kernel, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version df3f3bb5059d20ef094d6b2f0256c4bf4127a859 as the first without the flaw, so updating Linux Kernel to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux Kernel to df3f3bb5059d20ef094d6b2f0256c4bf4127a859 or a later version.
  2. Update SIMATIC S7-1500 TM MFP - GNU/Linux subsystem to V1.1 or a later version.
  3. Read the advisory on git.kernel.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Linux KernelLinux Kernelbefore df3f3bb5059d20ef094d6b2f0256c4bf4127a859df3f3bb5059d20ef094d6b2f0256c4bf4127a859
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystembefore V1.1V1.1
NetAppH300s FirmwareNot specified in the recordNot stated
NetAppH500s FirmwareNot specified in the recordNot stated
NetAppH700s FirmwareNot specified in the recordNot stated
NetAppH410s FirmwareNot specified in the recordNot stated
NetAppH410c FirmwareNot specified in the recordNot stated

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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighCNA (google.com)
CVSS 3.17.8HighNVD

Official description

io_uring use work_flags to determine which identity need to grab from the calling process to make sure it is consistent with the calling process when executing IORING_OP. Some operations are missing some types, which can lead to incorrect reference counts which can then lead to a double free. We recommend upgrading the kernel past commit df3f3bb5059d20ef094d6b2f0256c4bf4127a859

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

The underlying weakness: Double Free

The product calls free() twice on the same memory address.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
  • Use a static analysis tool to find double free instances.

More Double Free vulnerabilities (CWE-415)

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

Patches and release notes

Third-party and government advisories

Other vulnerabilities in Linux Kernel

All Linux Kernel vulnerabilities

Recent Double Free vulnerabilities

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