Source: secure@microsoft.com
Unspecified vulnerability in certain COM objects in Microsoft Office Web Components 2000 allows user-assisted remote attackers to execute arbitrary code via a crafted URL, aka "Office Web Components URL Parsing Vulnerability."
Microsoft Office Web Components 2000 suffers from an unspecified vulnerability that allows attackers to execute arbitrary code on a victim's machine. This vulnerability, triggered by a crafted URL, requires user interaction and can lead to complete system compromise, enabling attackers to install malware, steal data, or gain persistent access to the compromised system.
Step 1: Victim Interaction: The attacker crafts a malicious URL and entices a user to click it. This could be through a phishing email, a malicious website, or a compromised document.
Step 2: URL Parsing: The vulnerable COM object within Office Web Components 2000 attempts to parse the malicious URL. This parsing process is where the vulnerability resides.
Step 3: Input Handling Flaw: The parsing logic fails to properly validate the input within the URL. This could involve insufficient bounds checking, incorrect data type handling, or other vulnerabilities in the parsing routines.
Step 4: Code Execution: Due to the input handling flaw, the attacker's crafted data overwrites critical memory locations or triggers the execution of malicious code. This allows the attacker to execute arbitrary code on the victim's machine.
Step 5: Payload Execution: The attacker's code, now running with the privileges of the user, can perform various malicious actions, such as installing malware, stealing sensitive information, or establishing a backdoor for persistent access.
The vulnerability lies within the parsing of URLs by certain COM objects within Microsoft Office Web Components 2000. While the specific root cause is not explicitly detailed in the CVE, the description suggests a flaw in how the software handles user-supplied input within a URL. This could involve a buffer overflow, integer overflow, or other input validation errors. The crafted URL likely contains malicious data that, when processed by the vulnerable component, overwrites critical memory regions or triggers unintended code execution. The lack of specific details in the CVE suggests the vulnerability may be complex, involving multiple interacting components or a subtle flaw in the parsing logic.
Due to the age of the vulnerability and the lack of specific details, it's difficult to attribute this to specific APT groups. However, any APT group targeting Microsoft Office users would likely have exploited this vulnerability in the past. It is unlikely to be listed in CISA KEV due to its age and the lack of specific details.
Monitor network traffic for unusual HTTP requests containing suspicious URLs that might exploit the vulnerability.
Analyze Office Web Components logs for errors or unexpected behavior related to URL parsing.
Examine system logs for suspicious process creation or code execution related to the Office Web Components.
Implement file integrity monitoring to detect changes to Office Web Components files.
Monitor for the creation of new files or registry keys associated with malicious activity.
Use Endpoint Detection and Response (EDR) solutions to detect and respond to suspicious behavior.
Upgrade: The primary remediation is to upgrade to a supported version of Microsoft Office that does not include Office Web Components 2000. This is the most effective solution.
Disable Office Web Components: If upgrading is not immediately possible, disable Office Web Components if they are not required. This can be done through the registry or group policy.
User Education: Educate users about the dangers of clicking on suspicious links and opening attachments from untrusted sources.
Implement Network-Level Security: Use a web proxy or firewall to filter malicious URLs and prevent access to known malicious sites.
Apply Security Patches: Ensure that all security patches for Microsoft Office and the operating system are applied promptly.
Implement Least Privilege: Ensure users operate with the minimum necessary privileges to reduce the impact of a successful exploit.
Regularly Scan: Perform regular vulnerability scans to identify and address any existing vulnerabilities.