CVE-2023-41764: Microsoft Office Spoofing Vulnerability
CVE-2023-41764 is a spoofing vulnerability in Microsoft Office, rated Moderate by Microsoft, with a CVSS 3.1 base score of 5.5 (Medium). An attacker can exploit it by an attacker with local access, without any privileges and only if a user takes an action. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. The EPSS model estimates a 1.00% probability of exploitation activity in the next 30 days, higher than 63% of all scored vulnerabilities. Microsoft released the fix on 12 September 2023 in the September 2023 Patch Tuesday, delivered through 4 security updates (KB5002457, KB5002498, KB5002100, KB5002477). It affects 11 products in 1 product family (Microsoft Office).
Key facts
- CVE ID
- CVE-2023-41764
- Severity
- Medium CVSS 5.5
- Microsoft severity
- Moderate
- Impact
- Spoofing
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- Weakness
- CWE-347
- EPSS
- 1.00% (percentile 63%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- September 2023 Patch Tuesday
- Product families
- Microsoft Office
CVSS score and vector
Microsoft scores CVE-2023-41764 at 5.5 (temporal 4.8) using CVSS 3.1. Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Local |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality impact | None |
| Integrity impact | High |
| Availability impact | None |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Frequently asked questions (Microsoft)
According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?
Exploitation of the vulnerability requires that a user open a specially crafted file.
- In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file.
- In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) containing a specially crafted file designed to exploit the vulnerability.
An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file.
According to the CVSS metric, the attack vector is local (AV:L) but no privileges are required (PR:N) and user interaction is required (UI:R). How could an attacker exploit this spoofing vulnerability?
The attack itself is carried out locally by a user with authentication to the targeted system. An attacker could exploit the vulnerability by convincing a victim, through social engineering, to download and open a specially crafted file from a website which could lead to a local attack on the victim computer.
According to the CVSS metric, successful exploitation of this vulnerability could lead to total loss of integrity (I:H)? What does that mean for this vulnerability?
The vulnerability could allow an unauthenticated attacker to insert malicious content into a document which then passes the authentication check when a partial signature is present.
Affected products (11)
Microsoft Office
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft Office 2019 for 32-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office 2019 for 64-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft 365 Apps for Enterprise for 32-bit Systems | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office LTSC 2021 for 64-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office LTSC 2021 for 32-bit editions | Click to Run | Security Update | https://aka.ms/OfficeSecurityReleases | No |
| Microsoft Office 2016 (32-bit edition) | KB5002457 KB5002498 KB5002100 | Security Update Security Update Security Update | 16.0.5413.1000 16.0.5413.1000 16.0.5413.1000 | Maybe Maybe Maybe |
| Microsoft Office 2016 (64-bit edition) | KB5002457 KB5002498 KB5002100 | Security Update Security Update Security Update | 16.0.5413.1000 16.0.5413.1000 16.0.5413.1000 | Maybe Maybe Maybe |
| Microsoft Office 2013 RT Service Pack 1 | KB5002477 | Security Update | 15.0.5589.1000 | Maybe |
| Microsoft Office 2013 Service Pack 1 (32-bit editions) | KB5002477 | Security Update | 15.0.5589.1000 | Maybe |
| Microsoft Office 2013 Service Pack 1 (64-bit editions) | KB5002477 | Security Update | 15.0.5589.1000 | Maybe |
Security updates (4)
NIST NVD data
- NVD status
- Modified
- NVD CVSS
- 5.5 (MEDIUM)
- NVD weakness
- CWE-347
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| 365 apps (x64) | all listed versions |
| 365 apps (x86) | all listed versions |
| office 2013 (x64) | all listed versions |
| office 2013 (x86) | all listed versions |
| office 2013 | all listed versions |
| office 2016 (x64) | all listed versions |
| office 2016 (x86) | all listed versions |
| office 2019 (x64) | all listed versions |
| office 2019 (x86) | all listed versions |
| office long term servicing channel 2021 (x64) | all listed versions |
| office long term servicing channel 2021 (x86) | all listed versions |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-41764 (Patch, Vendor Advisory)
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-41764 (Patch, Vendor Advisory)
Acknowledgments
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |