CVE-2025-24990: Microsoft Windows Untrusted Pointer Dereference Vulnerability

What it is

Microsoft is aware of vulnerabilities in the third party Agere Modem driver that ships natively with supported Windows operating systems. This is an announcement of the upcoming removal of ltmdm64.sys driver. The driver has been removed in the October cumulative update. Fax modem hardware dependent on this specific driver will no longer work on Windows. Microsoft recommends removing any existing dependencies on this hardware.

Exploitation evidence

First exploit evidence seen: 2025-10-14 (earliest date across the sources below).

Exploited in the wild

• CISA KEV: listed since 2025-10-14. Source

Public exploit code

GitHub proof-of-concept repositories

2 public repositories from 2 accounts, first seen 2025-10-16. Most starred: moiz-2x/CVE-2025-24990_POC (58 stars), view repository.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: CISA KEV · nomi-sec/PoC-in-GitHub.

How to fix it

CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. (source: CISA KEV)

Fixed versions

• microsoft windows 10 1507: upgrade to 10.0.10240.21161 or later
• microsoft windows 10 1607: upgrade to 10.0.14393.8519 or later
• microsoft windows 10 1809: upgrade to 10.0.17763.7919 or later
• microsoft windows 10 21h2: upgrade to 10.0.19044.6456 or later
• microsoft windows 10 22h2: upgrade to 10.0.19045.6456 or later
• microsoft windows 11 22h2: upgrade to 10.0.22621.6060 or later
• microsoft windows 11 24h2: upgrade to 10.0.26100.6899 or later
• microsoft windows 11 25h2: upgrade to 10.0.26200.6899 or later
• microsoft windows server 2019: upgrade to 10.0.17763.7919 or later
• microsoft windows server 2022: upgrade to 10.0.20348.4294 or later
• microsoft windows server 2022 23h2: upgrade to 10.0.25398.1913 or later

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

• https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-24990 (CISA KEV notes)
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-24990 (Vendor Advisory)
• https://www.vicarius.io/vsociety/posts/cve-2025-24990-mitigation-script-elevation-of-privilege-vulnerability-in-agere-modem-driver-affecting-windows (Mitigation, Third Party Advisory)

Detection Generic guidance

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.