SB20250211114 - Multiple vulnerabilities in Microsoft Excel

Description

This security bulletin contains information about 6 secuirty vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2025-21386)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the target system.

2) Use-after-free (CVE-ID: CVE-2025-21387)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the target system.

3) Heap-based buffer overflow (CVE-ID: CVE-2025-21390)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

4) Out-of-bounds read (CVE-ID: CVE-2025-21383)

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition in Microsoft Excel. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger an out-of-bounds read error and read contents of memory on the system.

5) Use-after-free (CVE-ID: CVE-2025-21394)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the system.

6) Untrusted Pointer Dereference (CVE-ID: CVE-2025-21381)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to untrusted pointer dereference in Microsoft Excel. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the system.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21386
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21387
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21390
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21383
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21394
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-21381