CVE-2025-21354
Published: 14 January 2025
Summary
CVE-2025-21354 is a high-severity Untrusted Pointer Dereference (CWE-822) vulnerability in Microsoft Office Long Term Servicing Channel. Its CVSS base score is 8.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked in the top 17.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly remediates the Microsoft Excel RCE vulnerability stemming from CWE-822 untrusted pointer dereference by requiring timely application of vendor patches.
Implements memory safeguards such as ASLR and DEP that comprehensively mitigate exploitation of untrusted pointer dereference leading to arbitrary code execution.
Provides process isolation to limit the impact of RCE within the Excel instance, containing potential code execution to the application's execution domain.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability is a client-side RCE in Microsoft Excel allowing arbitrary code execution with no user interaction, directly mapping to exploitation for client execution.
NVD Description
Microsoft Excel Remote Code Execution Vulnerability
Deeper analysisAI
CVE-2025-21354 is a Remote Code Execution vulnerability in Microsoft Excel. Published on 2025-01-14, it carries a CVSS v3.1 base score of 8.4 (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and is associated with CWE-822 (Untrusted Pointer Dereference) along with NVD-CWE-noinfo.
The vulnerability can be exploited by a local attacker requiring low complexity, no privileges, and no user interaction. Successful exploitation enables the attacker to execute arbitrary code with high impacts on confidentiality, integrity, and availability within the affected Excel instance.
The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21354 provides details on mitigation, including available patches and recommended actions for security practitioners.
Details
- CWE(s)