Remote Code Execution in Microsoft Office Excel Malformed Object Handling
CVE-2009-0238 is a memory corruption vulnerability in Microsoft Office Excel and related components. A remote attacker can trigger the flaw by persuading a user to open a specially crafted Excel document containing a malformed object. When the file is opened, Excel attempts to access an invalid object in memory, leading to memory corruption and enabling arbitrary code execution in the context of the logged-on user. Affected products include Microsoft Office Excel 2000 SP3, 2002 SP3, 2003 SP3, and 2007 SP1; Excel Viewer 2003 Gold and SP3; Excel Viewer; the Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP1; and Excel in Microsoft Office 2004 and 2008 for Mac. Microsoft stated the issue was publicly disclosed and exploited in the wild, including by Trojan.Mdropper.AC, and addressed it in MS09-009 by changing how Excel opens Excel files.
Are you exposed to this one?
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
21 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A Microsoft Office Excel remote code execution vulnerability triggered by opening a specially crafted Excel file, causing invalid memory access and memory corruption that can lead to arbitrary code execution.
A critical Microsoft Excel remote code execution vulnerability triggered by opening a specially crafted Excel document containing a malformed object.
A critical remote code execution vulnerability in Microsoft Excel that is triggered when a victim opens a specially crafted Excel document containing a malformed object.
A remote code execution vulnerability in Microsoft Office Excel triggered by opening a specially crafted Excel file; this issue was publicly disclosed and was being exploited at the time of bulletin release.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.