Apple iOS, iPadOS, and macOS ImageIO Buffer Overflow
CVE-2023-41064 is a high-severity buffer copy without checking size of input vulnerability in macOS 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 unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists versions 12.6, 11.7, 13.5 as the first without the flaw, so updating macOS to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on September 11, 2023, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update macOS to 12.6 or 11.7 or 13.5, whichever matches your release line, or a later version.
- Update iOS and iPadOS to 16.6 or 15.7, whichever matches your release line, or a later version.
- Update iPadOS to 15.7.9 or 16.6.1, whichever matches your release line, or a later version.
- CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apple | macOS | before 12.6; before 11.7; before 13.5 | 12.6, 11.7, 13.5 |
| Apple | iOS and iPadOS | before 16.6; before 15.7 | 16.6, 15.7 |
| Apple | iPadOS | before 15.7.9; 16.0 up to, but not including, 16.6.1 | 15.7.9, 16.6.1 |
| Apple | Iphone OS | before 15.7.9; 16.0 up to, but not including, 16.6.1 | 15.7.9, 16.6.1 |
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
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- 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:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 16.6.1 and iPadOS 16.6.1, macOS Monterey 12.6.9, macOS Ventura 13.5.2, iOS 15.7.9 and iPadOS 15.7.9, macOS Big Sur 11.7.10. Processing a maliciously crafted image may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Buffer Copy without Checking Size of Input
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
More Buffer Copy without Checking Size of Input vulnerabilities (CWE-120)
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- support.apple.com/en-us/HT213905Release Notes
- support.apple.com/en-us/HT213906Release Notes
- support.apple.com/en-us/HT213913Release Notes
- support.apple.com/en-us/HT213914Release Notes
- support.apple.com/en-us/HT213915Release Notes
- support.apple.com/kb/HT213913Release Notes
- support.apple.com/kb/HT213915Release Notes
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-41064US Government Resource
Other references
- openwall.com/lists/oss-security/2023/09/21/4Mailing List
Other vulnerabilities in macOS
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Buffer Copy without Checking Size of Input vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.