CVE-2009-0901

The Active Template Library (ATL) in Microsoft Visual Studio .NET 2003 SP1, Visual Studio 2005 SP1 and 2008 Gold, and Visual C++ 2005 SP1 and 2008 Gold and SP1; and Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold, SP1, and SP2, and Server 2008 Gold and SP2; does not prevent VariantClear calls on an uninitialized VARIANT, which allows remote attackers to execute arbitrary code via a malformed stream to an ATL (1) component or (2) control, related to ATL headers and error handling, aka "ATL Uninitialized Object Vulnerability."

Published: 2009-07-29 Last update: 2026-05-27 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2009-0901 is rated High Risk (72.3/100): CVSS High severity, with high exploitation likelihood (EPSS 82.53%, 99th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +2.36% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2009-0901

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 80.17% 82.53% +2.36%
2 2026-04-19 65.35% 80.17% +14.82%
3 2026-02-14 65.35%

Full EPSS history (30 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-0901

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
9.3 2.0 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
8.6 10.0 [email protected]

Weakness enumeration for CVE-2009-0901

GitHub Security Advisory for CVE-2009-0901

GHSA-5q85-2xfh-7gpf · Severity: high — The Active Template Library (ATL) in Microsoft Visual Studio .NET 2003 SP1, Visual Studio 2005...

NVD evaluator notes for CVE-2009-0901

Impact: Please refer to this link http://www.microsoft.com/technet/security/Bulletin/MS09-035.mspx for mitigating factors and additional information.

Affected software / configurations for CVE-2009-0901

Vendor Product Version Raw CPE
microsoft visual_c\+\+ 2005 cpe:2.3:a:microsoft:visual_c\+\+:2005:sp1_redistribution_pkg:*:*:*:*:*:*
microsoft visual_c\+\+ 2008 cpe:2.3:a:microsoft:visual_c\+\+:2008:redistribution_pkg:*:*:*:*:*:*
microsoft visual_c\+\+ 2008 cpe:2.3:a:microsoft:visual_c\+\+:2008:sp1_redistribution_pkg:*:*:*:*:*:*
microsoft visual_studio 2005 cpe:2.3:a:microsoft:visual_studio:2005:sp1:*:*:*:*:*:*
microsoft visual_studio 2005 cpe:2.3:a:microsoft:visual_studio:2005:sp1:64_bit_hosted_visual_c\+\+_tools:*:*:*:*:*
microsoft visual_studio 2008 cpe:2.3:a:microsoft:visual_studio:2008:*:*:*:*:*:*:*
microsoft visual_studio 2008 cpe:2.3:a:microsoft:visual_studio:2008:sp1:*:*:*:*:*:*
microsoft visual_studio_.net 2003 cpe:2.3:a:microsoft:visual_studio_.net:2003:sp1:*:*:*:*:*:*

References for CVE-2009-0901

URL Tags
http://blogs.technet.com/srd/archive/2009/08/11/ms09-037-why-we-are-using-cve-s-already-used-in-ms09-035.aspx
http://marc.info/?l=bugtraq&m=126592505426855&w=2
http://secunia.com/advisories/35967
http://secunia.com/advisories/36187
http://secunia.com/advisories/36374
http://secunia.com/advisories/36746
http://sunsolve.sun.com/search/document.do?assetkey=1-66-266108-1
http://www.adobe.com/support/security/advisories/apsa09-04.html Patch
http://www.adobe.com/support/security/bulletins/apsb09-10.html
http://www.adobe.com/support/security/bulletins/apsb09-11.html Patch
http://www.adobe.com/support/security/bulletins/apsb09-13.html
http://www.novell.com/support/viewContent.do?externalId=7004997&sliceId=1
http://www.securityfocus.com/bid/35832 Patch
http://www.us-cert.gov/cas/techalerts/TA09-195A.html US Government Resource
http://www.us-cert.gov/cas/techalerts/TA09-223A.html US Government Resource
http://www.us-cert.gov/cas/techalerts/TA09-286A.html US Government Resource
http://www.vupen.com/english/advisories/2009/2034
http://www.vupen.com/english/advisories/2009/2232
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-035
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-037
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-060
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6289
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6311
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6373
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7581
cvelogic Threat Intelligence