CyberSecBulletin
CVE-2023-36495NVD status: Modified

tvOS: Integer Overflow or Wraparound

Published Updated By the CyberSecBulletin desk

CVE-2023-36495 is a critical-severity integer overflow or wraparound vulnerability in tvOS from Apple, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 16.6 as the first without the flaw, so updating tvOS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.27% chance of exploitation within 30 days, higher than 70% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update tvOS to 16.6 or a later version.
  2. Update iOS and iPadOS to 16.6 or 15.7, whichever matches your release line, or a later version.
  3. Update macOS to 13.5 or 12.6, whichever matches your release line, or a later version.
  4. Read the advisory on support.apple.com for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
AppletvOSbefore 16.616.6
AppleiOS and iPadOSbefore 16.6; before 15.716.6, 15.7
ApplemacOSbefore 13.5; before 12.613.5, 12.6
ApplewatchOSbefore 9.69.6
AppleiPadOSbefore 15.7.8; 16.0 up to, but not including, 16.615.7.8, 16.6
AppleIphone OSbefore 15.7.8; 16.0 up to, but not including, 16.615.7.8, 16.6

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

An integer overflow was addressed with improved input validation. This issue is fixed in watchOS 9.6, macOS Monterey 12.6.8, iOS 15.7.8 and iPadOS 15.7.8, tvOS 16.6, iOS 16.6 and iPadOS 16.6, macOS Ventura 13.5. 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: Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How developers prevent this class of flaw

  • Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).

More Integer Overflow or Wraparound vulnerabilities (CWE-190)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in tvOS

All tvOS vulnerabilities

Recent Integer Overflow or Wraparound vulnerabilities

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