Edge on Android CVE-2025-49755: UI Spoofing Risk and Mitigation

Microsoft’s Security Response Center has published an advisory for CVE-2025-49755, a user‑interface (UI) misrepresentation — spoofing — vulnerability affecting Microsoft Edge (Chromium‑based) on Android devices, a flaw that allows a remote attacker to present misleading or falsified UI elements to a user and thereby increase the likelihood of phishing, credential theft, or unwanted actions in a mobile browsing session. (msrc.microsoft.com)

Background​

Spoofing vulnerabilities in mobile browsers are a recurring class of risk: they occur when a browser’s UI can be manipulated so that critical information (such as the address bar, origin indicators, or security chrome) is displayed incorrectly or is visually decoupled from the underlying content. The Common Weakness Enumeration that best describes this behaviour is CWE‑451: User Interface (UI) Misrepresentation of Critical Information — a category Microsoft has used repeatedly for similar mobile Edge issues. (cvedetails.com)
Mobile browsers are particularly sensitive to UI manipulation because screen space is limited, controls are often condensed, and users rely on visual cues (URL, padlock icon, origin labels) that are easier to spoof on small viewports. Past Edge and Chromium advisories show that UI spoofing on Android or iOS can be mounted via crafted HTML, navigation tricks, or misuse of overlays and frames; vendors typically fix these with rendering, navigation-handling, or chrome‑binding changes in Chromium and upstream code. (cybersecurity-help.cz, avesnetsec.com)

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What Microsoft Says About CVE‑2025‑49755​

Microsoft’s entry for CVE‑2025‑49755 classifies the vulnerability as a UI misrepresentation (spoofing) in Microsoft Edge for Android and identifies the exploit vector as network‑accessible — meaning a remote attacker can deliver the malicious content over the web. The vendor advisory page is the authoritative listing for the CVE and will contain any vendor-supplied mitigation notes, affected version strings, and patch/hotfix references as they become available. (msrc.microsoft.com)
Important — Microsoft advisories for related Edge spoofing CVEs typically include:

• A short description of the weakness and exploit vector.
• A CWE assignment (commonly CWE‑451).
• The affected product family and, in many cases, a “fixed in” version string when a patch is released.

However, at the time of this reporting, the MSRC entry for CVE‑2025‑49755 contains a concise technical descriptor with minimal public reproduction details; Microsoft often withholds exploit specifics to limit mass exploitation before broad patch rollout. Readers should treat the MSRC page as the canonical source for the current patch status and version-level impact. (msrc.microsoft.com)

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How This Type of Spoofing Works — Technical Overview​

Mobile browser UI spoofing generally follows a few well‑trodden patterns. An attacker’s page (or a page they trick a user into visiting) uses one or more of these techniques:

• Manipulating navigation or window history so that the address bar displays a legitimate URL while the visible page content is attacker‑controlled.
• Using full‑screen overlays, popups, or frames to present cloned UI elements (fake address bars, padlocks, or sign‑in dialogs) that mimic system chrome.
• Exploiting timing or race conditions in how the renderer updates the visible URL vs. the page content after rapid redirects or scripted navigation.
• Abusing platform‑specific webview or browser quirks that fail to tightly bind the displayed origin indicator to the active document.

A successful exploit leads to a mismatch between what the user sees (trusted site indicators) and what the browser is actually displaying (malicious content). The attacker’s objective is social engineering: convince the user to enter credentials, authorize a transaction, or install a payload. Prior Edge mobile CVEs have used similar UI‑spoofing vectors; vendors closed them by ensuring the address bar and security iconography are always tied to the active, validated document and by hardening navigation handling in Chromium. (cve.news, avesnetsec.com)

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Risk Assessment: Who’s Affected and How Dangerous Is This?​

• Affected product family: Microsoft Edge (Chromium‑based) on Android (MSRC lists Android as impacted for CVE‑2025‑49755). Because Edge shares Chromium internals, similar flaws may show up in other Chromium‑derived builds; however, exploitability is vendor‑specific until upstream fixes are merged. (msrc.microsoft.com)
• Exploit vector: Network — remote attacker-hosted web content. That makes the attack surface broad: any Android Edge user who visits a crafted URL or clicks a malicious link is potentially at risk. (msrc.microsoft.com)
• Typical impact: Credential theft and phishing via believable UI mimicry. Confidentiality is the primary exposure; integrity and availability impacts are typically limited for plain spoofing vulnerabilities. Prior Edge spoofing CVEs received medium CVSS ratings in the 4–6 range, reflecting that these are network‑accessible but often require user interaction (clicks, form entry). Independent trackers for similar Edge spoofing CVEs assigned CVSS ~5.3 as a median value. (cvedetails.com, feedly.com)

Caveat: As of this article’s publication the vendor advisory for CVE‑2025‑49755 does not publish a public CVSS score or a fixed version on the MSRC page view available without JavaScript rendering. That lack of a public score or exact fixed‑in build increases uncertainty for risk scoring; treat the vulnerability as actionable and patch‑worthy but consult MSRC for definitive fix guidance. (msrc.microsoft.com)

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Why Mobile UI Spoofing Is Especially Effective​

• Smaller viewports hide cues. On Android phones the address bar and padlock often occupy limited space; small manipulations are harder to spot than on desktop.
• Users are habituated to mobile sign‑in flows. People sign in frequently on phones (apps and websites), lowering suspicion when prompted.
• Link delivery is effortless. Attackers can distribute deceptive links via SMS, social apps, in‑app browsers, or email; a single click on mobile often opens a new tab where the spoof executes.
• Extensions and defenses are limited. Mobile browsers lack the richer extension ecosystem available on desktop that can add anti‑phishing layers; users rely more on the browser’s built‑in protections. Historical Edge mobile patches have therefore emphasized native browser hardening. (cybersecurity-help.cz, avesnetsec.com)

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What Is Known and What Is Not (Verification Summary)​

Known:

• Microsoft lists CVE‑2025‑49755 as a User interface (ui) misrepresentation (spoofing) issue for Microsoft Edge on Android. The MSRC advisory is the authoritative vendor entry. (msrc.microsoft.com)

Verified via independent historical comparison:

• Similar mobile Edge/UI spoofing CVEs have been issued and patched in earlier months; those prior advisories used CWE‑451 and were assigned medium severity levels in public trackers. This historical pattern suggests how Microsoft will likely respond (patch + fixed version + advisory notes). (cvedetails.com, feedly.com)

Not publicly verifiable at time of writing:

• Exact affected version strings, a CVSS base score, and public proof‑of‑concept details for CVE‑2025‑49755 were not visible on widely indexed mirrors. The MSRC entry exists but its page content requires the security update guide’s interactive JS view to reveal full metadata; third‑party aggregators did not return a complete, corroborating record for this specific CVE number at press time. Readers should check the MSRC listing for updates. (msrc.microsoft.com)

(When vendor pages are terse, independent aggregators such as NVD, CVE Details, or security blogs usually publish corroborating metadata; if those are missing for a given CVE, treat some numeric details as unverified until cross‑checked against MSRC or NVD entries.) (cvedetails.com, nvd.nist.gov)

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Practical Mitigations for Consumers (Immediate to 48 Hours)​

• Update Microsoft Edge immediately.
• Open Edge on Android, go to Settings → About Microsoft Edge and allow the browser to check for updates. Edge stable channel updates typically roll out via Google Play or in‑app mechanisms. If the MSRC advisory lists a fixed version, ensure your build equals or exceeds that version. Patching is the primary mitigation. (msrc.microsoft.com, feedly.com)
• Be skeptical of links and one‑tap sign‑ins.
• Do not sign in or enter credentials after following an unsolicited link. Prefer to open known sites by typing the URL or using a trusted bookmark.
• Enable browser anti‑phishing features.
• Leave SmartScreen (or equivalent protection) enabled in Edge’s Privacy settings, and enable HTTPS‑only mode where available.
• Use strong account protections.
• Turn on multi‑factor authentication (MFA) for email, banking, and other critical accounts so stolen passwords alone are insufficient.
• Limit risk surface on mobile.
• Avoid using in‑app browsers for sensitive authentication; open sensitive links in a full browser that you control. Remove or restrict untrusted browser extensions and debug-level webviews. (cybersecurity-help.cz)

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Enterprise and IT‑Admin Actions (Immediate to 7 Days)​

• Inventory and patch: Map Edge for Android usage across managed devices and roll out the vendor‑recommended update via your MDM solution as soon as Microsoft publishes fixed builds.
• Enforce mobile update policy: Use MDM to require the minimum safe Edge build number once Microsoft specifies it in MSRC.
• Deploy multi‑layer defenses: Use secure web gateways, DNS filtering, and mobile threat defense (MTD) solutions to block known malicious domains and mitigate drive‑by link risk.
• Email and messaging hygiene: Strengthen gateway filtering and add URL rewriting/proxying to validate outgoing links and scan destinations.
• User awareness: Deploy a short, targeted notification explaining that a browser UI spoofing issue exists and listing the safe behavior (do not enter credentials on pages opened via unsolicited links; verify URLs; use MFA).
• Logging and detection: Tune SIEM and mobile device logs to look for mass‑phishing spikes, credential‑harvest patterns, or multiple failed authentication attempts following link campaigns.

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Detection and Hunting Tips​

• Hunt for abnormal redirect chains in web proxy logs and HTTP referrer anomalies that show rapid scripted redirects prior to page load completion.
• Search for user reports of login requests where the user insists the URL looked “correct” — mismatch between claimed origin and final destination is a strong indicator.
• Look for spikes in credential‑related failures from Android endpoints following email/SMS campaigns; map these against web proxy logs for candidate spoofed pages.
• If Microsoft provides detection headers or transport rule snippets (they have done so for other spoofing advisories in the past), deploy those immediately across your edge mail/web infrastructure.

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Why Patching Matters Even When Exploits Are Not Publicly Known​

History shows that UI spoofing vulnerabilities, while not always immediately critical in terms of remote code execution, directly enable highly effective social‑engineering campaigns. Attackers often combine spoofing with phishing distribution (email, SMS) to scale credential theft. Microsoft and other vendors have repeatedly prioritized timely fixes for these issues because the operational impact — account takeovers, fraudulent transactions, and data exfiltration — is high even when the bug does not lead to system compromise by itself. The correct posture is to treat such bugs as high‑priority for patching and mitigations. (cvedetails.com, feedly.com)

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Strengths and Weaknesses of Microsoft’s Response Pattern​

Strengths:

• Microsoft publishes CVEs and maintains an MSRC update guide that centralizes vendor advisories, making it straightforward for administrators to track fixes when they are released. (msrc.microsoft.com)
• Historically, Microsoft has pushed quick updates for Chromium‑derived issues in Edge, and when necessary they coordinate fixes with upstream Chromium and other vendors.

Risks / Weaknesses:

• MSRC advisory pages sometimes present minimal public technical detail (deliberate to limit exploit diffusion) and rely on interactive pages or KB articles to convey full metadata; when that metadata is terse, third‑party aggregators may lag in providing version or CVSS details, complicating risk scoring for defenders. This is evident when a CVE is listed but lacks open CVSS and fixed‑in details in public mirrors. (msrc.microsoft.com, nvd.nist.gov)
• Chromium’s shared codebase is a double‑edged sword: fixes upstream help many vendors, but disparate release schedules mean some browsers or builds may remain vulnerable longer than others.

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How to Stay Informed (Authoritative Sources)​

• Microsoft Security Response Center (MSRC) update guide — vendor authoritative CVE page for Edge advisories. (msrc.microsoft.com)
• Public vulnerability trackers and security blogs (NVD, CVE Details, security vendor blogs) for independent corroboration and CVSS/EPS scoring as those databases update. (cvedetails.com, nvd.nist.gov)
• Managed‑security feeds and vulnerability management tools (Qualys, Rapid7, Tenable) that push detection signatures and scanner checks for fixed versions once vendors publish fixes. (feedly.com)

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Recommended Action Plan (Concise, Priority‑Ordered)​

• Check MSRC for CVE‑2025‑49755 for the “fixed in” build and immediate patch guidance; apply the update to all managed devices as soon as a vendor fix is published. (msrc.microsoft.com)
• If an immediate patch is not yet available, raise blocking rules in your web gateway for high‑risk domains and require users to access critical services only through managed, tested browsers.
• Enforce MFA, rotate any credentials suspected of exposure, and audit account access logs for anomalies.
• Push a user notice that describes the risk and safe behaviors for mobile browsing — do not click unknown links, verify URLs, and report suspicious sign‑in prompts.
• Monitor third‑party vulnerability feeds and exploit intelligence for any public PoC or active exploitation reports; escalate patching windows if evidence of exploitation emerges. (feedly.com)

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Final Analysis and Conclusion​

CVE‑2025‑49755 is part of a continuing stream of UI‑spoofing issues targeting Chromium‑based browsers on mobile devices. These flaws are less flashy than remote code execution vulnerabilities but are practically dangerous because they directly facilitate social‑engineering attacks that result in credential theft and account compromise. Microsoft’s MSRC listing confirms the issue exists for Edge on Android; however, public detail (CVSS, exact affected build, and patch references) may be limited at first and requires close attention to the MSRC advisory for authoritative updates. (msrc.microsoft.com)
Defenders should prioritize patching when Microsoft publishes a fixed build, harden browser and gateway policies in the interim, and treat any unusual login or redirect activity with suspicion. Because these vulnerabilities often require only user interaction plus a crafted page, the most effective mitigations combine prompt patching with account hardening (MFA) and user awareness. Historical patterns show vendors fix UI spoofing quickly when vulnerabilities are disclosed; the practical task for security teams is closing the window between disclosure and deployment. (cvedetails.com, avesnetsec.com)
Caveat: Some numeric specifics for CVE‑2025‑49755 (for example, a vendor‑assigned CVSS score or precise “fixed‑in” version string) were not available in widely indexed mirrors at the time of writing; confirm those details on the Microsoft Security Response Center page for the CVE and follow Microsoft’s official update guidance as your single source of truth. (msrc.microsoft.com)

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Users and administrators should act now: verify Edge for Android is updated across devices, confirm MFA is enforced for critical services, and treat unexpected sign‑in prompts or links received via SMS/email with heightened skepticism until MSRC confirms patched builds are widely deployed.

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Source: MSRC Security Update Guide - Microsoft Security Response Center