CVE-2011-1216 in Lotus Notes
Summary
by MITRE
Stack-based buffer overflow in assr.dll in Autonomy KeyView, as used in IBM Lotus Notes before 8.5.2 FP3, allows remote attackers to execute arbitrary code via crafted tag data in an Applix spreadsheet attachment, aka SPR PRAD8823A7.
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Analysis
by VulDB Data Team • 11/07/2021
The vulnerability CVE-2011-1216 represents a critical stack-based buffer overflow flaw in the assr.dll library component of Autonomy KeyView software, which was integrated into IBM Lotus Notes versions prior to 8.5.2 Fix Pack 3. This vulnerability arises from insufficient input validation when processing Applix spreadsheet attachments, specifically when handling crafted tag data within these files. The flaw exists in the manner in which the software parses and processes structured data within spreadsheet formats, creating an opportunity for malicious actors to exploit memory corruption through carefully constructed input payloads.
The technical implementation of this vulnerability stems from improper bounds checking within the assr.dll module responsible for processing Applix spreadsheet files. When IBM Lotus Notes encounters an Applix spreadsheet attachment, the software utilizes Autonomy KeyView's parsing capabilities to interpret the file structure and extract relevant data. The buffer overflow occurs during the processing of tag data within the spreadsheet, where the software fails to validate the length of incoming data against the allocated buffer space on the stack. This allows an attacker to overwrite adjacent memory locations, potentially corrupting the program's execution flow and enabling arbitrary code execution.
From an operational perspective, this vulnerability presents a significant threat to organizations using affected versions of IBM Lotus Notes, as it enables remote code execution through email attachments without requiring authentication or privileged access. Attackers can craft malicious Applix spreadsheet files containing oversized tag data that triggers the buffer overflow when the recipient opens the attachment. The impact extends beyond individual user compromise to potentially enable lateral movement within network environments, as compromised email systems can serve as entry points for broader attacks. The vulnerability's remote exploitability and lack of user interaction requirements make it particularly dangerous in enterprise environments where email is a primary communication channel.
The vulnerability maps to CWE-121 Stack-based Buffer Overflow, which is classified under the Common Weakness Enumeration framework as a fundamental memory safety issue. This weakness is further categorized under the ATT&CK framework's technique T1059.007 for Command and Scripting Interpreter, as successful exploitation would enable attackers to execute arbitrary commands on the target system. Organizations should prioritize immediate patching of affected systems, as the vulnerability was addressed through IBM's 8.5.2 Fix Pack 3 release, which included updated versions of the Autonomy KeyView components. Additional mitigations may include implementing email filtering rules to block Applix spreadsheet attachments, disabling automatic attachment opening, and conducting security awareness training to reduce the risk of users inadvertently opening malicious attachments.
The broader implications of this vulnerability highlight the challenges of integrating third-party libraries into enterprise applications, where security flaws in component software can have cascading effects across multiple products. This case demonstrates the importance of regular security assessments of integrated components and the need for timely patch management processes. Organizations should maintain comprehensive inventory of all software components and their associated security vulnerabilities to effectively manage risk exposure. The vulnerability also underscores the necessity of secure coding practices in library development, particularly around input validation and memory management, to prevent similar issues from occurring in future software releases.