Safari: Improper Control of Generation of Code
CVE-2023-42890 is a high-severity improper control of generation of code vulnerability in Safari from Apple, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 17.2 as the first without the flaw, so updating Safari to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 3.21% chance of exploitation within 30 days, higher than 88% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Safari to 17.2 or a later version.
- Update iOS and iPadOS to 17.2 or a later version.
- Update tvOS to 17.2 or a later version.
- Read the advisory on support.apple.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- 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 | Safari | before 17.2 | 17.2 |
| Apple | iOS and iPadOS | before 17.2 | 17.2 |
| Apple | tvOS | before 17.2 | 17.2 |
| Apple | macOS | before 14.2 | 14.2 |
| Apple | watchOS | before 10.2 | 10.2 |
| Apple | iPadOS | before 17.2 | 17.2 |
| Apple | Iphone OS | before 17.2 | 17.2 |
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
- 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:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
The issue was addressed with improved memory handling. This issue is fixed in Safari 17.2, macOS Sonoma 14.2, watchOS 10.2, iOS 17.2 and iPadOS 17.2, tvOS 17.2. Processing web content may lead to arbitrary code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- support.apple.com/en-us/HT214035Release Notes
- support.apple.com/en-us/HT214036Release Notes
- support.apple.com/en-us/HT214039Release Notes
- support.apple.com/en-us/HT214040Release Notes
- support.apple.com/en-us/HT214041Release Notes
Third-party and government advisories
- seclists.org/fulldisclosure/2023/Dec/12Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2023/Dec/13Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2023/Dec/6Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2023/Dec/7Mailing List, Third Party Advisory
- seclists.org/fulldisclosure/2023/Dec/9Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2023/12/18/1Mailing List, Third Party Advisory
- security.gentoo.org/glsa/202401-33Third Party Advisory
Other references
Other vulnerabilities in Safari
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 10.0 Critical severity
- 8.8 High severity
- 8.8 High severity
Recent Improper Control of Generation of Code vulnerabilities
- 8.8 High severity
- 8.2 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
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