CVE-2008-1108 in Evolution
Summary
by MITRE
Buffer overflow in Evolution 2.22.1, when the ITip Formatter plugin is disabled, allows remote attackers to execute arbitrary code via a long timezone string in an iCalendar attachment.
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Analysis
by VulDB Data Team • 08/11/2019
The vulnerability identified as CVE-2008-1108 represents a critical buffer overflow flaw within the Evolution email client version 2.22.1 that specifically manifests when the ITip Formatter plugin remains disabled. This issue arises from inadequate input validation mechanisms within the iCalendar attachment processing functionality, creating a pathway for remote code execution attacks. The flaw exploits the client's handling of timezone data within calendar event files, where maliciously crafted timezone strings can exceed allocated buffer boundaries and overwrite adjacent memory regions. The vulnerability demonstrates characteristics consistent with CWE-121, heap-based buffer overflow, as the malicious input causes memory corruption that can be leveraged by attackers to inject and execute arbitrary code on the target system. Attackers can exploit this weakness by crafting specially formatted iCalendar attachments containing excessively long timezone identifiers that trigger the buffer overflow during parsing operations.
The technical implementation of this vulnerability involves the Evolution client's calendar processing module failing to properly bounds-check timezone string lengths when parsing iCalendar data. When an attacker sends an email containing an iCalendar attachment with an oversized timezone specification, the parsing routine does not validate the input length against the allocated buffer space, resulting in memory corruption. This memory corruption can overwrite return addresses, function pointers, or other critical control data structures, enabling attackers to redirect execution flow and inject malicious code. The vulnerability is particularly concerning because it operates in a remote attack scenario where no user interaction is required beyond receiving the malicious email, making it highly exploitable in automated attack campaigns. The specific condition requiring the ITip Formatter plugin to be disabled suggests that the vulnerability may be triggered through different code paths depending on plugin configurations, though the core buffer overflow remains consistent.
The operational impact of CVE-2008-1108 extends beyond simple remote code execution to encompass potential system compromise and data exfiltration capabilities. Successful exploitation can result in complete system control, allowing attackers to install backdoors, modify system configurations, or access sensitive user data stored within the Evolution client environment. The vulnerability affects organizations relying on Evolution for email and calendar management, particularly those without proper email filtering or sandboxing measures in place. Attackers leveraging this flaw can potentially establish persistent access to corporate email systems, creating opportunities for advanced persistent threats and lateral movement within network environments. The vulnerability's exploitation requires minimal user interaction beyond email receipt, making it particularly dangerous in enterprise environments where users may inadvertently receive malicious attachments. This characteristic aligns with ATT&CK technique T1190, exploitation of remote services, and demonstrates how client-side vulnerabilities can serve as initial access vectors for broader security breaches.
Mitigation strategies for CVE-2008-1108 should prioritize immediate patch application to Evolution 2.22.1, as the vendor released updates addressing the buffer overflow conditions. Organizations should implement email filtering measures to detect and quarantine suspicious iCalendar attachments, particularly those containing malformed timezone data. Network-level protections including email security gateways and content inspection systems can help identify and block malicious calendar attachments before they reach end-user systems. System hardening measures such as disabling unnecessary plugins, implementing privilege separation, and applying memory protection mechanisms like stack canaries can provide additional defense layers. Regular security assessments should verify that Evolution installations have been updated to versions containing the appropriate patches, while monitoring systems should be configured to detect unusual email processing activities that might indicate exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date software and implementing defense-in-depth strategies to protect against client-side exploitation vectors. Organizations should also consider implementing user education programs to raise awareness about suspicious email attachments and the risks associated with calendar data processing.