CVE-2025-54111: Local Privilege Escalation in Windows DatePickerFlyout (UI XAML)

CVE-2025-54111 — Windows UI XAML Phone DatePickerFlyout: Use‑After‑Free Leads to Local Privilege Escalation​

By [Your Name], WindowsForum.com — Sep 9, 2025
Summary

• Microsoft has assigned CVE‑2025‑54111 to a use‑after‑free vulnerability in the Windows UI XAML Phone DatePickerFlyout control. The flaw can be triggered by an authenticated (local) attacker and may allow elevation of privileges on an affected Windows host. (msrc.microsoft.com)
• At time of writing there are no widely published proof‑of‑concept exploits or third‑party advisories for this CVE beyond Microsoft's advisory; Microsoft’s Security Update Guide is the authoritative source for affected builds and the remediation steps. (msrc.microsoft.com)
• Administrators should treat this as a local privilege‑escalation risk: prioritize deployment of the Microsoft update, harden endpoint configurations, and monitor for related XAML crashes and unusual local activity while the patch is being applied. (msrc.microsoft.com)

What Microsoft says (short)
Microsoft’s vulnerability entry for CVE‑2025‑54111 identifies the vulnerable component as Windows UI XAML Phone DatePickerFlyout and classifies the impact as an elevation‑of‑privilege (EoP) vulnerability caused by a use‑after‑free condition. The vendor advisory is the source of truth for exact affected product/OS build ranges and the security update (KB) that fixes it. Administrators should consult Microsoft’s Security Update Guide and apply the supplied fixes as soon as practical. (msrc.microsoft.com)
Technical background — what is DatePickerFlyout and why it matters

• DatePickerFlyout is a XAML control (a “flyout”) used primarily by phone/compact UI scenarios in the Windows UI XAML stack to let users pick a date. In many versions of Windows, XAML controls run as part of user interactive processes and are reachable from applications that host XAML content. Mismanagement of XAML object lifetimes can lead to memory‑safety bugs such as use‑after‑free. (blog.csdn.net)
• Historically, XAML and the UI stack have been the source of privilege and sandbox‑escape issues when diagnostic APIs or IPC channels are misused; previous XAML‑related vulnerabilities have allowed escalation when the UI host or diagnostics channels were not properly access‑checked. That context makes any memory‑safety flaw in XAML a meaningful EoP risk to investigate and patch quickly. (m417z.com)

What “use‑after‑free” means in plain English

• A use‑after‑free occurs when code continues to access an object after it has been freed (returned to the allocator). If an attacker can influence the timing or contents of memory at that address, they can often cause the program to execute attacker‑controlled data or code (depending on exploit mitigations present).
• On modern Windows builds exploitability depends on mitigations (ASLR, DEP, CFG, control‑flow protections) and the specifics of the object layout; but even when remote code execution is difficult, use‑after‑free can frequently be converted into local privilege escalation (EoP) if the vulnerable component is reachable from a less‑privileged process and interacts with higher‑privilege code paths. Microsoft’s advisory identifies this instance as an EoP scenario. (msrc.microsoft.com)

Attack vector and prerequisites

• Attack type: local (authenticated) attacker — the vector requires the attacker to run code on the target machine in the context of an unprivileged user. The flaw is not described as remotely exploitable over a network. (msrc.microsoft.com)
• Preconditions: attacker must be able to interact with the XAML DatePickerFlyout (e.g., open or manipulate the control from a user process) or otherwise cause the vulnerable code to execute with controlled inputs. As with many UI‑stack EoP issues, a local foothold is required to escalate to higher privileges. (msrc.microsoft.com)
• Realistic exploitation scenario: an attacker with local code execution (e.g., via a low‑privilege userland process or malicious application the user ran) triggers the DatePickerFlyout in a way that races or coerces the underlying object to be freed while still referenced; the resulting use‑after‑free is abused to corrupt memory structures and gain elevated privileges. The exact exploitation technique would depend on the patched code paths and Windows mitigations in place. (msrc.microsoft.com)

Exploitability and threat assessment

• Likelihood of public exploit: As of Sep 9, 2025, there are no widely published PoCs or Proof‑of‑Exploit code for CVE‑2025‑54111 beyond Microsoft’s advisory. That does not mean exploit code will not appear quickly — local EoP bugs (especially in platform code) are attractive targets for red teams and malware authors. Treat the absence of public PoC as temporary and do not postpone patching. (msrc.microsoft.com)
• Difficulty: medium. Exploiting a modern Windows use‑after‑free to reliably gain escalated privileges requires low‑level knowledge of Windows internals and dependable exploitation techniques; however, attackers with local code execution and persistence are commonly capable of turning such flaws into reliable EoP exploits. Prior vulnerability history in the XAML stack shows skilled researchers can weaponize memory‑corruption bugs against Windows UI processes. (m417z.com, github.com)
• Impact: High for affected machines where an unauthenticated or low‑privileged local attacker can run code (e.g., multi‑user systems, shared workstations, developer boxes, or systems where attackers can trick a user into running an app). If exploited, the attacker could gain SYSTEM or administrative privileges. (msrc.microsoft.com)

Affected platforms and patch status

• The single authoritative public record for the specific product/component and fix is Microsoft’s Security Update Guide entry for CVE‑2025‑54111; that page contains the affected OS builds, update KB numbers, and whether the update was shipped as part of a Microsoft monthly rollup or out‑of‑cycle patch. Administrators must consult that Microsoft entry (and their internal update catalog/WSUS) to determine which KB addresses the bug for their particular Windows version and build. (msrc.microsoft.com)
• Action: Deploy the Microsoft security update that specifically addresses CVE‑2025‑54111 to all affected Windows hosts. If you use centralized patch management (SCCM/WSUS/Intune), confirm the KB appears in your catalog and then schedule an expedited deployment to higher‑risk devices (domain controllers, jump boxes, admin workstations). (msrc.microsoft.com)

Interim mitigations and workarounds (if you can’t patch immediately)
Microsoft often provides mitigation guidance in its advisory. If a patch cannot be applied immediately, consider the following general, temporary mitigations (note: these are generic and may or may not be applicable to this specific advisory; check the MSRC entry before relying on them):

• Reduce attack surface: prevent unprivileged users and untrusted applications from running on sensitive machines. Enforce application allow‑listing (SmartScreen/AppLocker/WDAC) and restrict software installation rights. (msrc.microsoft.com)
• Limit local access: remove non‑essential local accounts, enforce least privilege for daily use (don’t use admin accounts for routine tasks), and restrict interactive logons to sensitive hosts. (msrc.microsoft.com)
• Monitor and detection: enable endpoint detection and response (EDR) rules for suspicious DLL injection, process crashes in XAML‑related modules, and rapid privilege changes; watch for crash signatures referencing Microsoft.UI.Xaml or DatePickerFlyout usage as potential exploitation indicators (application crash windows or event log entries may be an early sign). GitHub issue threads and community reports historically show XAML crashes before/after patches — treat recurring XAML crashes as high priority for investigation. (github.com, m417z.com)
• If Microsoft documents a specific registry or Group Policy workaround, follow that guidance only as a short‑term measure; Microsoft will mark such workarounds explicitly in the advisory if they’re available. Always remove temporary mitigations once the official update is applied. (msrc.microsoft.com)

Detection and monitoring recommendations

• Look for crashes in the event log where the faulting module is Microsoft.UI.Xaml.dll (or other XAML UI DLLs) and pair that with abnormal process behavior, elevation attempts, or unexpected service creation. Attackers often cause controlled crashes as part of exploitation attempts or stability‑probing. (github.com)
• EDR/Telemetry: enable rules to alert on:
• Local processes invoking COM/XAML diagnostic APIs in unusual contexts.
• Unexpected token elevation attempts (e.g., Lsass accesses, process token duplication).
• Process memory corruption patterns (heap spraying, rapid allocation/free patterns).
• Hardening logs: retain application crash dumps and collect full memory dumps of suspect processes for forensic analysis — those dumps may be necessary to triage a successful exploit or to support threat hunting. (m417z.com)

Developer and vendor guidance (for app makers)

• If your application hosts XAML controls or uses DatePickerFlyout (or similar flyouts), ensure you run on patched Windows builds and validate your code handles Flyout lifetimes safely. Where possible:
• Avoid keeping stale pointers to UI elements that can be freed asynchronously.
• Use safe XAML patterns and event unsubscription to prevent callbacks touching freed objects.
• Test boundary conditions: rapid open/close, reentrancy, and error paths where objects may be destroyed while still referenced.
• Report any suspicious behavior or reproducible app‑level crashes to Microsoft via the normal security/contact channels so they can be correlated with platform fixes. (msrc.microsoft.com)

Responsible disclosure and timeline (what we know)

• Microsoft’s advisory is the primary disclosure for CVE‑2025‑54111. The vendor normally coordinates disclosure, assigns a CVE, and publishes fixes as part of the Security Update Guide or a monthly Patch Tuesday release; if your organization relies on Microsoft updates, monitor the MSRC advisory for exact KB numbers and release notes. (msrc.microsoft.com)
• Our independent web searches (public trackers, security vendors, exploit repositories) show no major third‑party write‑ups or public exploit code for CVE‑2025‑54111 at time of writing; this means defenders have a chance to patch before PoCs proliferate — but don’t rely on this window lasting. (msrc.microsoft.com)

What a complete mitigation plan looks like (recommended)

• Immediately validate the Microsoft advisory for CVE‑2025‑54111 and determine which KB/patch corresponds to each supported Windows version in your environment. Apply the update to a test ring first, then to high‑risk machines, and finally broadly. (msrc.microsoft.com)
• Where patch rollout will be delayed more than 72 hours for any machines, apply temporary mitigations: restrict local accounts, enable strict app allow‑listing, and block execution of untrusted code on those hosts. (msrc.microsoft.com)
• Update EDR and SIEM detection rules to flag Microsoft.UI.Xaml crashes, suspicious XAML IPC activity, and attempts to escalate privileges locally. Collect and retain crash dumps for forensic analysis. (github.com)
• Perform focused hunting: search for unusual local processes that recently spawned elevated processes, locate unknown scheduled tasks, or look for recent service installations. If suspicious activity is found, isolate affected hosts and investigate full memory/process dumps. (m417z.com)
• After remediation, validate systems using centralized compliance reporting (SCCM/Intune/Azure Update Compliance) to confirm the KB is installed everywhere and that no systems remain on vulnerable builds. (msrc.microsoft.com)

Final takeaways

• CVE‑2025‑54111 is a local elevation‑of‑privilege vulnerability rooted in a use‑after‑free within the Windows UI XAML Phone DatePickerFlyout control. Microsoft’s advisory is the authoritative record and provides the remediation KB(s). Apply Microsoft’s updates promptly. (msrc.microsoft.com)
• While no public exploit/PoC was found at time of writing, the vulnerability class (use‑after‑free in XAML) has a historical precedent for being weaponized; treat this as a high‑priority patch. (m417z.com)
• If you need help locating the specific KB for your environment or want a checklist for staged rollout, reply with your environment details (Windows versions and whether you manage updates with WSUS/SCCM/Intune) and I’ll provide a prioritized deployment plan and detection rule examples you can paste into your EDR/SIEM.

Sources consulted

• Microsoft Security Update Guide — CVE‑2025‑54111 advisory. (msrc.microsoft.com)
• Microsoft MSRC (Patch Tuesday / Security Update guidance) — general patching & deployment guidance. (msrc.microsoft.com)
• Microsoft UI XAML community issue tracker (DropDownButton / Flyout crash reports) — background on XAML flyout stability and crash patterns. (github.com)
• Public write‑ups on past XAML diagnostic and XAML‑based privilege escalations (context on exploitation approaches and mitigations). (m417z.com)

If you’d like

• I can produce a one‑page executive briefing (suitable for IT leadership) that lists affected host counts, patching priority, and expected downtime impact.
• I can also generate sample detection signatures and a short PowerShell script to inventory Windows builds against the specific KB once you tell me which KB number corresponds to your build (I can pull that from MSRC if you want me to look it up for your Windows versions).

---

Source: MSRC Security Update Guide - Microsoft Security Response Center