CVE-2015-2545: Microsoft Office Malformed EPS File Vulnerability

CVE-2015-2545 is a vulnerability in Microsoft Office that lets remote attackers run arbitrary code by supplying a crafted EPS image. It matters because Office is widely deployed on endpoints that open documents and images from email, shares, and the web; successful abuse can give an attacker code execution in the context of the user who opens the file.

Public detail is limited to the vendor and CISA descriptions. Confirm exact affected products, builds, and fixes against the Microsoft advisory before acting.

How it works

The weakness is classified as CWE-20 (Improper Input Validation). In this class of flaw, the application does not adequately check or reject malformed input before processing it. Here, Microsoft Office processes an Encapsulated PostScript (EPS) image that has been deliberately malformed. When the crafted EPS is handled, the lack of proper validation can allow the attacker’s data to influence program execution and achieve arbitrary code execution.

An attacker typically delivers the malicious EPS inside or alongside an Office document or as a standalone image the user is induced to open. No further exploit mechanics are provided in the public summary; treat any claimed technique, payload, or reliability claim as unconfirmed until verified against the vendor advisory and your own analysis.

Am I affected? How to find it in your systems

Microsoft Office is commonly installed on Windows workstations, laptops, and some terminal or VDI environments used for document editing and email. Inventory every host that has Office components capable of handling EPS or related graphics filters.

• Enumerate installed Office suites and click-to-run or MSI builds via your software inventory, SCCM/ConfigMgr, Intune, or equivalent endpoint management tools.
• Identify machines where users routinely open untrusted documents or images (mail gateways, file shares, collaboration platforms).
• Check whether EPS import or graphics filters are enabled; if your environment has disabled EPS handling as a prior hardening step, note that configuration.
• Review the Microsoft advisory for the precise SKUs and versions in scope; do not assume coverage from version numbers not stated in that advisory.

Telemetry signs of attempted exploitation are generic for this class: unexpected Office process crashes when rendering images, creation of unusual child processes from WINWORD.EXE, EXCEL.EXE, or related Office binaries after a user opens a file containing EPS content, and inbound files with EPS payloads flagged by mail or content filters. Correlate with EDR process trees and file-open events. Confirm any indicators against vendor and threat-intel guidance rather than relying on unverified signatures.

How to remediate

Patch first. Apply the updates Microsoft released for this vulnerability, following the vendor instructions referenced by CISA (“Apply updates per vendor instructions”). Use your standard enterprise deployment channel to push the security update to all affected Office installations and verify installation success.

• After patching, validate that the fixed builds are present across the estate.
• Where feasible, reduce the attack surface for this class of issue by limiting or disabling unnecessary graphics filters and EPS processing if business use allows.
• Keep Office and the underlying OS on a supported, regularly updated baseline so subsequent fixes are not delayed.
• Enforce least privilege so that code execution in the user context has limited impact (standard user rights, Application Guard or similar isolation where available).

If you can't patch immediately

Until the vendor update is deployed everywhere, reduce exposure with compensating controls:

• Block or quarantine Office documents and EPS files from untrusted sources at the mail gateway and web proxy; strip or sandbox attachments that contain EPS content.
• Use attack-surface reduction rules, application control, or a WAF/virtual-patching layer that can detect malformed EPS or known Office exploit patterns—tune and test to avoid breaking legitimate workflows.
• Segment high-risk user populations and restrict outbound connectivity from workstations that must still open untrusted files.
• Temporarily disable EPS and related image filters via Office or Group Policy configuration if your environment can operate without them; confirm the exact setting names and scope in Microsoft documentation.
• Heighten monitoring: alert on Office spawning unexpected children, unusual module loads, or crashes tied to image rendering, and ensure EDR is in blocking mode where policy allows.

These measures lower risk but do not replace the patch. Schedule the update as soon as operationally possible.

If your data may have been exposed

Actively exploited remote-code-execution flaws in desktop productivity software are a common path into endpoints and, from there, into broader network access and data theft. Public information for this CVE does not document ransomware use; treat any compromise as a full incident until scoped. If you suspect exploitation, isolate affected hosts, preserve memory and disk evidence, reset credentials, and follow your incident-response process. As a quick external check, you can run a free exposure scan of your email addresses against known breach datasets to see whether associated credentials or identities have appeared in prior dumps, then force password changes and enable phishing-resistant MFA where needed.