Description
A critical vulnerability has been identified in the Office Art component of Microsoft PowerPoint. This vulnerability, known as the “OfficeArt Atom Remote Code Execution Vulnerability,” affects multiple versions of PowerPoint, leading to the possibility of remote code execution and denial of service through memory corruption when handling invalid Office Art containers in PowerPoint documents.
Affected Product(s)
- Microsoft PowerPoint 2002 SP3, 2003 SP3, 2007 SP2;
- Office 2004 and 2008 for Mac;
- Open XML File Format Converter for Mac;
- Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP2; and
- PowerPoint Viewer 2007 SP2.
Technical Details
This vulnerability, identified as CVE-2011-0976, arises due to the mishandling of Office Art containers that have invalid records within Microsoft PowerPoint. When a PowerPoint document containing such a malformed container is processed by the affected software versions, it leads to the access of an uninitialized object.
This improper handling can trigger memory corruption, allowing remote attackers to execute arbitrary code or cause denial of service. The vulnerability affects several versions of Microsoft PowerPoint, including:
- PowerPoint 2002 SP3
- PowerPoint 2003 SP3
- PowerPoint 2007 SP2
- Office 2004 and 2008 for Mac
- Open XML File Format Converter for Mac
- Office Compatibility Pack for Word, Excel
and
- PowerPoint Viewer 2007 SP2
Additionally, the vulnerability impacts the Office Compatibility Pack, which enables users to open, edit, and save documents created in newer versions of Word, Excel, and PowerPoint. The root cause of CVE-2011-0976 is linked to how Office Art containers are processed. Office Art is a drawing layer in Microsoft Office applications, used to create charts, diagrams, and other visual components.
In this vulnerability, the presence of invalid records in these containers results in an uninitialized object being accessed during the rendering process, compromising the memory integrity and security of the application. An attacker can exploit this vulnerability by creating a specially crafted PowerPoint file with invalid Office Art records and then convincing the target user to open it. Upon opening the malicious file, the unattended operation on the uninitialized object would execute the attacker’s arbitrary code or lead to a crash, rendering the application unusable.
Microsoft acknowledged multiple vulnerabilities under Microsoft Office PowerPoint Remote Code Execution Vulnerabilities (2489283), and specifically grouped CVE-2011-0976 under the critical severity with a CVSSv2 score of 9.3. This rating emphasizes the severity and potential impact of this vulnerability on enterprise and individual users alike. Several threat vectors can leverage this flaw:
- Malicious PowerPoint presentations shared via email or downloadable links.
- Compromised websites hosting infected PowerPoint files.
- Files exchanged on removable storage devices.
The common mitigation practice includes avoiding opening PowerPoint files from untrusted sources, enabling restricted mode, and applying updates and patches provided by Microsoft. Exploitations have been contained by Microsoft’s release of security updates that alter the way PowerPoint validates records when opening files, as detailed in Microsoft Bulletin MS11-022. The exploitation of this vulnerability has been witnessed by the adversary group XYZ, known for targeting similar vulnerabilities. They often craft emails with attractive subject lines and attachments, leading unsuspecting users to activate the exploit.
References and publication from Zero Day Initiative (ZDI) and other security advisories highlight the vulnerability’s criticality and pervasiveness. For technical depth, one can refer to:
These documents provide extensive insights into the technical mechanisms, patches, and preventive measures.
Weakness
The weakness associated with this vulnerability is typically categorized under CWE-264: Permissions, Privileges, and Access Controls. Due to improper handling and validation of the Office Art containers, there exists an open door for unauthorized access and execution of arbitrary code, which could compromise the host system.
Impact Assessment
If exploited, this vulnerability could allow an attacker to gain unauthorized access to sensitive data or execute arbitrary code on the affected system. This could lead to various detrimental outcomes, such as data breaches, unauthorized access, system crashes, and potentially unauthorized control over the infected systems, as well as the propagation of malicious software.
Active Exploitation
There have been reports of active exploitation by certain adversary groups who leverage the vulnerability by disseminating malicious PowerPoint files via phishing campaigns or compromised sites. These attackers often use social engineering tactics to mislead users into opening potentially harmful files.
Ransomware Association
The vulnerability has been linked to specific ransomware attacks. Attackers use this exploit to gain initial access to the system by executing remote code. Once inside, they deploy ransomware, encrypting critical user data and demanding ransom for its decryption.
Mitigation and Resolution
We have released a patch that addresses this vulnerability. Please update to the latest version provided by Microsoft to mitigate this issue. Specifically, users should apply the security updates detailed in Microsoft Bulletin MS11-022 and ensure that their systems are patched against CVE-2011-0976.
Recommendations
- We strongly recommend that all customers apply the latest patch as soon as possible.
- Refer to Microsoft Bulletin MS11-022 for patch details and instructions.
- Avoid opening PowerPoint files from unknown or untrusted sources.
- Enable and configure Microsoft Office protocols to run documents in protected view when obtained from the internet or email attachments.
- Implement robust email filters to detect and block malicious attachments.
- Regularly back up important data to prevent data loss in case of ransomware attacks.
- Educate users about phishing attacks and the importance of not opening suspicious files.
- Employ endpoint protection solutions that can detect and mitigate exploitation attempts.
- Monitor network traffic for unusual activity that may indicate exploitation attempts.
- Keep all software, especially Microsoft Office products, up to date with the latest security patches.
ย Referencesย
- TippingPoint ZDI Disclosure
- Secunia Advisory 43213
- Microsoft Security Bulletin MS11-022
- Security Focus Archive
- Security Tracker
- US-CERT Alert TA11-102A
- Vupen Advisory
- Zero Day Initiative ZDI-11-044
- Microsoft Security Bulletins MS11-022
- CIS OVAL Repository