CVE-2015-2502: Microsoft Internet Explorer Memory Corruption Vulnerability

CVE-2015-2502 is a memory corruption vulnerability in Microsoft Internet Explorer. An attacker who successfully exploits it can run code in the context of the browser process or cause the browser to crash, resulting in denial of service. For organizations still running Internet Explorer in any capacity, this class of flaw matters because browsers process untrusted web content by design and are a common initial access path.

Public detail on exact affected builds and exploit mechanics is limited here; confirm all version and patch specifics against the Microsoft vendor advisory before acting.

How it works

The underlying weakness is CWE-119: improper restriction of operations within the bounds of a memory buffer. In browser engines this typically means crafted web content (or content loaded through the browser) can corrupt memory structures the renderer or scripting engine relies on. Once memory is corrupted, an attacker may achieve arbitrary code execution under the privileges of the logged-on user or simply crash the process for a denial-of-service effect.

No exploit code or detailed trigger conditions are provided in the available facts. Treat any untrusted page, advertisement, or embedded content as a potential delivery vehicle for this class of issue until the browser is fully patched. Confirm the precise attack surface and fixed builds in the vendor advisory.

Am I affected? How to find it in your systems

Internet Explorer historically shipped with Windows client and server editions and may still be present even when Microsoft Edge is the default browser. Inventory steps:

• Enumerate installed browsers and versions across endpoints and jump hosts (software inventory, SCCM/ConfigMgr, Intune, or equivalent asset tools).
• Check whether IE is still enabled via Windows Features, enterprise mode site lists, or Group Policy that forces IE for legacy line-of-business applications.
• Identify kiosks, VDI pools, Citrix/RDS hosts, and administrative workstations that may still launch iexplore.exe.
• Review application compatibility inventories for any internal web apps that explicitly require Internet Explorer.

Telemetry signs of attempted exploitation for memory-corruption browser bugs generally include unexpected IE process crashes, faulting modules in the browser or related DLLs, and sudden child processes spawned from iexplore.exe. Correlate crash dumps and EDR process-creation events with web browsing activity. Exact indicators are not supplied in the facts; validate detection logic against your EDR and the vendor advisory.

How to remediate

Patch first. CISA’s required action is to apply updates per vendor instructions. Obtain and deploy the security update that Microsoft issued for CVE-2015-2502; confirm the KB article and applicable Windows/IE versions directly from the Microsoft advisory and your patch-management catalog.

After patching:

• Restart affected systems as required by the update.
• Verify the update is present via your configuration-management or vulnerability-scanning tools.
• Where possible, migrate remaining IE-dependent workflows to a supported modern browser and retire Internet Explorer to shrink future attack surface.
• Enforce least privilege so that even successful browser code execution runs as a standard user rather than an administrator.

If you can't patch immediately

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

• Network segmentation and egress filtering: limit which systems can reach the open internet with IE, and restrict those hosts to necessary destinations only.
• Application control: block or constrain iexplore.exe where it is not required; use AppLocker, WDAC, or equivalent.
• Disable or harden unnecessary IE features and legacy document modes via Group Policy if your environment still permits configuration of the browser.
• Virtual patching / web filtering: block known-malicious categories and untrusted zones at the proxy or secure-web gateway; consider IPS rules that target browser memory-corruption patterns if your vendor supplies them for this CVE family.
• Heightened monitoring: alert on IE crashes, unusual child processes, and memory-corruption related fault signatures on high-value endpoints.

These measures only buy time; they do not replace the official update.

If your data may have been exposed

Actively exploited browser vulnerabilities are a common route to endpoint compromise and subsequent data theft. The facts do not document ransomware use for this CVE, but any successful code execution can lead to credential theft, lateral movement, or exfiltration. If you suspect exploitation, isolate the host, preserve memory and disk evidence, and begin incident-response procedures. As a quick external check, users can run a free exposure scan of their email addresses against known breach data sets to see whether credentials or personal information have already appeared in public dumps.