CVE-2015-2425: Microsoft Internet Explorer Memory Corruption Vulnerability

How it works

CVE-2015-2425 is a memory corruption vulnerability in Microsoft Internet Explorer, classified under CWE-119 (improper restriction of operations within the bounds of a memory buffer). In this class of flaw, the browser mishandles certain memory operations when processing content, which can leave the process in an inconsistent state.

According to the CISA summary, a remote attacker can abuse the condition to execute code or cause a denial-of-service. In practical terms for this product class, that typically means an attacker crafts web content or related input that the browser renders; successful exploitation can lead to arbitrary code running in the context of the browser process or can crash the browser. Exact trigger conditions, attack vectors, and exploitation mechanics are not detailed in the provided facts and must be confirmed against the vendor advisory. No specific exploit code or technique is described here.

Am I affected? How to find it in your systems

This issue affects Microsoft Internet Explorer. Internet Explorer historically shipped with Windows client and server editions and was often the default or embedded browser for legacy line-of-business apps, ActiveX-dependent portals, and internal web tools. Even on systems that have moved to newer browsers, IE components or compatibility modes may still be present.

Practical inventory steps:

• Enumerate endpoints and servers still running Internet Explorer or hosting IE-based applications (software inventory, SCCM/Intune/endpoint management reports, or simple checks for iexplore.exe and related browser helper objects).
• Identify versions and patch levels of Internet Explorer and the underlying Windows OS; compare them to the fixed builds listed in the Microsoft advisory for CVE-2015-2425. Do not rely on assumed version ranges—confirm against the vendor advisory.
• Note configurations that increase exposure: users browsing untrusted sites, IE running with elevated privileges, or legacy intranet zones with relaxed security settings.
• For exploitation signs, review endpoint and browser crash telemetry, unexpected iexplore.exe child processes or network connections, and EDR alerts related to memory corruption or code injection in the browser process. Public detail on specific log indicators for this CVE is limited; treat anomalous browser behavior as worth investigating in context.

How to remediate

Patch first. CISA’s required action is to apply updates per vendor instructions. Obtain and deploy the Microsoft security update that addresses CVE-2015-2425 on all affected systems, following your standard test-and-rollout process. Confirm the exact KBs or cumulative updates in the official Microsoft advisory rather than assuming package names.

After patching, harden for this weakness class:

• Prefer modern, supported browsers for daily use and restrict Internet Explorer to only those legacy applications that still require it.
• Enforce least privilege so the browser does not run as administrator.
• Keep Windows and browser-related components on a regular patch cadence; memory-corruption issues are frequently addressed in cumulative updates.
• Disable or tightly control unnecessary ActiveX, browser helper objects, and legacy document modes where business needs allow.

If you can't patch immediately

Until the vendor update can be applied, reduce risk with compensating controls:

• Network segmentation and egress controls: limit which systems can reach untrusted web content; place high-risk or unpatched endpoints in restricted VLANs.
• Application control / allowlisting: block or constrain iexplore.exe where it is not required, or run it only for approved internal sites.
• Virtual patching / content filtering: use a web proxy or secure web gateway to block known malicious categories and high-risk content types that commonly deliver browser exploits; any WAF or IPS signatures should be validated against vendor or security-vendor guidance for this CVE.
• Disable the affected feature path where feasible: move users off Internet Explorer to a supported browser, or use enterprise mode / site lists only for essential internal URLs.
• Heightened monitoring: alert on browser crashes, unusual child processes from iexplore.exe, and suspicious outbound connections from browser processes. Retain EDR and proxy logs for retrospective review.

These measures do not replace the patch; they only buy time. Schedule the official update as soon as possible.

If your data may have been exposed

Actively exploited browser memory-corruption vulnerabilities can lead to code execution, credential theft, or follow-on compromise, which in turn can result in data exposure. Known ransomware use is not documented for this CVE in the provided facts. If you suspect exploitation, isolate affected hosts, preserve forensic evidence, rotate credentials accessible from those systems, and follow your incident-response process. As a simple additional check, you can run a free exposure scan of your email addresses against known breach data to see whether associated accounts appear in prior publicly reported breaches.