CVE-2008-0110 in Outlook
Summary
by MITRE
Unspecified vulnerability in Microsoft Outlook in Office 2000 SP3, XP SP3, 2003 SP2 and Sp3, and Office System allows user-assisted remote attackers to execute arbitrary code via a crafted mailto URI.
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Analysis
by VulDB Data Team • 06/01/2025
The vulnerability identified as CVE-2008-0110 represents a critical security flaw in Microsoft Outlook applications across multiple versions including Office 2000 SP3, XP SP3, 2003 SP2, and Office System SP3. This vulnerability specifically affects the handling of mailto URI schemes within the email client, creating a potential attack vector that could be exploited by remote adversaries with user assistance. The unspecified nature of the vulnerability indicates that the exact technical mechanism remains undisclosed, though it clearly involves improper input validation or processing of URI schemes within the Outlook application context.
The technical flaw manifests through the improper handling of crafted mailto URIs that contain malicious payloads or malformed parameters. When a user clicks on a specially crafted mailto link, the Outlook client processes this URI without adequate sanitization or validation checks, potentially allowing arbitrary code execution on the victim's system. This type of vulnerability falls under the category of input validation flaws and could be classified as CWE-170, which deals with improper handling of input that could lead to security issues. The vulnerability specifically targets the email client's URI processing capabilities, making it particularly dangerous in phishing or social engineering scenarios where users might be tricked into clicking malicious links.
From an operational perspective, this vulnerability presents significant risks to enterprise environments where Outlook is widely deployed. The user-assisted nature of the attack means that successful exploitation requires user interaction, typically through clicking on a malicious link in an email or web page. However, the widespread use of Outlook across organizations makes this attack vector particularly effective, as users often trust email applications and may not recognize the danger of clicking on seemingly legitimate links. The impact extends beyond individual users to potentially compromise entire corporate networks, especially when combined with other attack vectors or when users have elevated privileges within the organization.
Security professionals should implement multiple layers of defense against this vulnerability, including email filtering solutions that can detect and block suspicious mailto URI patterns, user education programs to raise awareness about phishing attempts, and network monitoring to detect anomalous behavior. The ATT&CK framework categorizes this vulnerability under initial access and execution tactics, specifically targeting the 'Phishing' and 'Command and Scripting Interpreter' techniques. Organizations should prioritize patch management and ensure all Outlook installations are updated to versions that address this vulnerability, while also implementing email security solutions that can identify and neutralize malicious URI schemes before they reach end users. Additionally, administrators should consider implementing application whitelisting policies and restricting the execution of potentially dangerous URI schemes through group policies or security configurations.