CVE-2005-2550 in Evolution
Summary
by MITRE
Format string vulnerability in Evolution 1.4 through 2.3.6.1 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via the calendar entries such as task lists, which are not properly handled when the user selects the Calendars tab.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/08/2019
The vulnerability identified as CVE-2005-2550 represents a critical format string flaw within the Evolution email and calendar client version 1.4 through 2.3.6.1. This issue specifically affects the handling of calendar entries including task lists when users interact with the Calendars tab, creating a significant security risk that can be exploited remotely by malicious actors. The vulnerability stems from improper input validation and sanitization of calendar data, particularly when the application processes user-provided calendar entries that contain format specifiers. When a user selects the Calendars tab, the application fails to properly handle these malformed calendar entries, leading to potential buffer overflows and memory corruption issues that can result in application crashes or more severe exploitation outcomes.
The technical nature of this vulnerability aligns with CWE-134, which describes the weakness of using user-supplied format strings without proper validation or sanitization. This flaw enables attackers to craft specially formatted calendar entries containing format specifiers such as %s, %d, or %x that can be interpreted by the application's printf-family functions. The vulnerability occurs during the rendering process of calendar data when the application attempts to display task lists or other calendar entries without adequate protection against malicious input. The flaw is particularly dangerous because it can be triggered through normal user interaction with calendar data, requiring no special privileges or complex attack vectors beyond the ability to create calendar entries that can be viewed by the target user.
From an operational perspective, this vulnerability creates significant risk for organizations relying on Evolution for calendar management and collaboration. The remote exploitation capability means that attackers can potentially compromise systems simply by sending malicious calendar entries to users, making it particularly dangerous in enterprise environments where calendar sharing and collaboration are common practices. The potential for arbitrary code execution, while not guaranteed, represents a serious escalation risk that could allow attackers to gain full control over affected systems. The denial of service component alone can disrupt critical business operations by causing the calendar application to crash repeatedly, preventing users from accessing their schedule information and potentially affecting productivity across the organization.
The impact of this vulnerability extends beyond immediate system compromise to include broader security implications for email and calendar infrastructure. Organizations using Evolution in corporate environments face risks of data exposure, system availability disruption, and potential lateral movement opportunities if attackers successfully execute arbitrary code. The vulnerability affects a wide range of versions, making it particularly concerning for organizations that may not have immediate patching capabilities or may be running legacy systems. Security teams should consider this vulnerability as part of broader email and calendar security assessments, particularly when evaluating risks associated with user-generated content and collaborative applications. Mitigation strategies should include immediate patching of affected versions, implementation of calendar entry validation mechanisms, and network segmentation to limit potential attack surfaces.
The exploitation of this vulnerability aligns with several ATT&CK tactics including privilege escalation and defense evasion, as attackers can potentially use the format string vulnerability to establish persistent access or hide their activities within the calendar infrastructure. Organizations should implement comprehensive monitoring for unusual calendar entry creation patterns and consider deploying application whitelisting solutions to prevent execution of untrusted calendar data. The vulnerability also highlights the importance of input validation in collaborative applications and demonstrates how seemingly benign features like calendar sharing can become attack vectors when proper security controls are not implemented. Security professionals should treat this as a reminder of the critical importance of secure coding practices and the need for thorough testing of user input handling in all application components, particularly those that process external data sources.