CVE-2011-3827 in GroupWise
Summary
by MITRE
The iCalendar component in gwwww1.dll in GroupWise Internet Agent (GWIA) in Novell GroupWise 8.0 before Support Pack 3 allows remote attackers to cause a denial of service (out-of-bounds read and daemon crash) via a crafted date-time string in a .ics attachment.
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Analysis
by VulDB Data Team • 12/14/2021
The vulnerability identified as CVE-2011-3827 represents a critical security flaw in the GroupWise Internet Agent component of Novell GroupWise 8.0 prior to Support Pack 3. This issue resides within the iCalendar component implemented in the gwwww1.dll dynamic link library, which processes calendar data through .ics file attachments. The vulnerability manifests as an out-of-bounds read condition that occurs when the system encounters malformed date-time strings within iCalendar data structures, ultimately leading to daemon crashes and complete service disruption. The flaw demonstrates characteristics consistent with CWE-129, which addresses improper validation of array indices and bounds, making it particularly dangerous as it can be exploited remotely without authentication requirements.
The technical exploitation of this vulnerability occurs when a remote attacker crafts a malicious .ics attachment containing malformed date-time values that exceed the expected bounds of the iCalendar parser. The gwwww1.dll component fails to properly validate input parameters during the parsing of calendar events, specifically when processing datetime fields in the iCalendar format. This failure results in memory access violations that cause the GroupWise Internet Agent daemon to terminate unexpectedly. The vulnerability operates at the application layer and leverages the standard iCalendar protocol implementation, making it particularly difficult to detect as it appears to be legitimate calendar data processing. According to ATT&CK framework category T1499, this represents a denial of service attack that compromises system availability and can be classified under the technique of "Network Denial of Service" as it targets the network-facing daemon service.
The operational impact of CVE-2011-3827 extends beyond simple service disruption, as it can effectively paralyze calendar and scheduling functionality within GroupWise environments. Organizations relying on GroupWise for business-critical communications may experience complete loss of calendar synchronization capabilities, email scheduling features, and integrated collaboration services. The daemon crash creates a cascading effect that can impact multiple users simultaneously, particularly in enterprise environments where GroupWise serves as a central communication platform. System administrators face significant operational challenges as the service disruption is not easily recoverable without manual intervention, potentially requiring complete daemon restarts and system monitoring to prevent repeated exploitation attempts. This vulnerability aligns with ATT&CK technique T1566, which involves initial access through spearphishing attachments, as the attack vector typically involves sending malicious calendar attachments to unsuspecting users.
Mitigation strategies for CVE-2011-3827 require immediate implementation of vendor-provided patches and updates to GroupWise 8.0 systems. Organizations should prioritize applying Support Pack 3 or later versions that contain the necessary fixes for the iCalendar parsing routines. Network-level protections such as email filtering systems should be configured to scan and block .ics attachments from untrusted sources, while additional monitoring should be implemented to detect anomalous daemon behavior patterns. Security teams should also consider implementing network segmentation to limit the potential blast radius of successful exploitation attempts. The vulnerability demonstrates the importance of input validation and bounds checking in calendar and scheduling applications, aligning with industry best practices outlined in CWE-129 and other security standards. Regular vulnerability assessments and penetration testing should be conducted to identify similar input validation flaws in other calendar and collaboration systems within the enterprise environment.