3D Viewer: Heap-based Buffer Overflow
CVE-2024-20677 is a high-severity heap-based buffer overflow vulnerability in 3D Viewer from Microsoft, 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 version 7.2401.29012.0 as the first without the flaw, so updating 3D Viewer to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 3.26% chance of exploitation within 30 days, higher than 89% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update 3D Viewer to 7.2401.29012.0 or a later version.
- Update Microsoft Office 2019 to https://aka.ms/OfficeSecurityReleases or a later version.
- Update Microsoft 365 Apps for Enterprise to https://aka.ms/OfficeSecurityReleases or a later version.
- Read the advisory on msrc.microsoft.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 |
|---|---|---|---|
| Microsoft | 3D Viewer | 7.0.0 up to, but not including, 7.2401.29012.0 | 7.2401.29012.0 |
| Microsoft | Microsoft Office 2019 | 19.0.0 up to, but not including, https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 up to, but not including, https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office LTSC for Mac 2021 | 16.0.1 up to, but not including, 16.81.24011420 | 16.81.24011420 |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 up to, but not including, https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases |
| Microsoft | 365 Apps | Not specified in the record | Not stated |
| Microsoft | Office | 2019 | Not stated |
| Microsoft | Office Long Term Servicing Channel | 2021 | Not 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
- 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 CNA (microsoft.com).
Official description
A security vulnerability exists in FBX that could lead to remote code execution. To mitigate this vulnerability, the ability to insert FBX files has been disabled in Word, Excel, PowerPoint and Outlook for Windows and Mac. Versions of Office that had this feature enabled will no longer have access to it. This includes Office 2019, Office 2021, Office LTSC for Mac 2021, and Microsoft 365. As of February 13, 2024, the ability to insert FBX files has also been disabled in 3D Viewer. 3D models in Office documents that were previously inserted from a FBX file will continue to work as expected unless the Link to File option was chosen at insert time. This change is effective as of the January 9, 2024 security update.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Heap-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the heap.
How developers prevent this class of flaw
- Pre-design: Use a language or compiler that performs automatic bounds checking.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- 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.
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
Recent Heap-based Buffer Overflow vulnerabilities
- 7.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 9.8 Critical severity
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