CyberSecBulletin
CVE-2023-40396NVD status: Modified

iOS and iPadOS: Improper Neutralization of Special Elements used in a Command

Published Updated By the CyberSecBulletin desk

CVE-2023-40396 is a high-severity improper neutralization of special elements used in a command vulnerability in iOS and iPadOS from Apple, 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 17 as the first without the flaw, so updating iOS and iPadOS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.22% 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 iOS and iPadOS to 17 or a later version.
  2. Update tvOS to 17 or a later version.
  3. Update macOS to 14 or a later version.
  4. Read the advisory on support.apple.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
AppleiOS and iPadOSbefore 1717
AppletvOSbefore 1717
ApplemacOSbefore 1414
ApplewatchOSbefore 1010
Appleiosbefore 17.017.0
Appleipad_osbefore 17.017.0
AppleiPadOSbefore 17.017.0
AppleIphone OSbefore 17.017.0

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 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)

Official description

The issue was addressed with improved memory handling. This issue is fixed in iOS 17 and iPadOS 17, macOS Sonoma 14, watchOS 10, tvOS 17. An app may be able to execute arbitrary code with kernel privileges.

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

The underlying weakness: Improper Neutralization of Special Elements used in a Command

The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • If possible, ensure that all external commands called from the program are statically created.
  • Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.

More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)

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

Other vulnerabilities in iOS and iPadOS

All iOS and iPadOS vulnerabilities

Recent Improper Neutralization of Special Elements used in a Command vulnerabilities

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