CVE-2006-1540Office Code Injection
MSO.DLL in Microsoft Office 2000, Office XP (2002), and Office 2003 allows user-assisted attackers to cause a denial of service and execute arbitrary code via multiple attack vectors, as originally demonstrated using a crafted document record with a malformed string, as…
Published Mar 30, 2006 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-2006-1540 is a critical-severity vulnerability (CVSS 9.3 v2) affecting Office (Microsoft).
- It is exploited in the wild, listed in Industry KEV feed since Jul 11, 2006. A public exploit is reported by tracking sources, but no code link is listed yet.
- EPSS estimates a 29% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v2
9.3
AV:N/AC:M/Au:N/C:C/I:C/A:C
EPSS (30-day exploit likelihood)
29%
Higher than 98.1% of all scored CVEs
Exploit maturity
Exploited (KEV)
ATLAS score
56/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Jul 11, 2006
103 days after publication
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Exploited (KEV)
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
3
Reports of active use
Advisories And Exploit References
- advisory21012
- advisoryoffice-string-parse-bo(27607)
- advisoryoffice-property-string-bo(27609)
- advisoryoval:org.mitre.oval:def:639
- advisory1615
- advisoryVU#609868
Description
MSO.DLL in Microsoft Office 2000, Office XP (2002), and Office 2003 allows user-assisted attackers to cause a denial of service and execute arbitrary code via multiple attack vectors, as originally demonstrated using a crafted document record with a malformed string, as demonstrated by replacing a certain "01 00 00 00" byte sequence with an "FF FF FF FF" byte sequence, possibly causing an invalid array index, in (1) an Excel .xls document, which triggers an access violation in ole32.dll; (2) an Excel .xlw document, which triggers an access violation in excel.exe; (3) a Word document, which triggers an access violation in mso.dll in winword.exe; and (4) a PowerPoint document, which triggers an access violation in powerpnt.txt.
NOTE: after the initial disclosure, this issue was demonstrated by triggering an integer overflow using an inconsistent size for a Unicode "Sheet Name" string.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Jul 11, 2006 | n/a | Not reported |
Affected Products
15 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OfficeMicrosoft | 2000, 2000-sp1, 2000-sp3, 2003-sp1, 2003-sp2, 2003, 2004, v.x | n/a |
Timeline
Publicly disclosed
Mar 30, 2006
Added to Industry KEV feed
Jul 11, 2006
Last updated
Apr 15, 2026
Weakness Type
- CWE-94 Improper Control of Generation of Code ('Code Injection')
References
- advisory21012
- advisoryoffice-string-parse-bo(27607)
- advisoryoffice-property-string-bo(27609)
- advisoryoval:org.mitre.oval:def:639
- advisory1615
FAQ
Common Questions.
MSO.DLL in Microsoft Office 2000, Office XP (2002), and Office 2003 allows user-assisted attackers to cause a denial of service and execute arbitrary code via multiple attack vectors, as originally demonstrated using a crafted document record with a malformed string, as demonstrated by replacing a certain "01 00 00 00…
Affected: Office (Microsoft) versions 2000, 2000-sp1, 2000-sp3, 2003-sp1, 2003-sp2, 2003, 2004, v.x. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Jul 11, 2006.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
A public exploit is reported by tracking sources, but no code link is listed yet.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2006-1540 On Your Attack Surface?
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