CVE-2011-1217 in Lotus Notes
Summary
by MITRE
Buffer overflow in kpprzrdr.dll in Autonomy KeyView, as used in IBM Lotus Notes before 8.5.2 FP3, allows remote attackers to execute arbitrary code via a crafted .prz attachment. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 11/08/2021
The vulnerability identified as CVE-2011-1217 represents a critical buffer overflow flaw within the kpprzrdr.dll component of Autonomy KeyView technology, which was subsequently integrated into IBM Lotus Notes email client software. This vulnerability specifically affects versions of IBM Lotus Notes prior to 8.5.2 Fix Pack 3, creating a significant security risk that could be exploited by remote attackers to gain unauthorized system access. The flaw manifests when the vulnerable software processes specially crafted .prz attachment files, which are typically used for document conversion and rendering within the email environment.
The technical nature of this vulnerability stems from improper input validation and memory management within the kpprzrdr.dll library responsible for handling .prz file format processing. When a user opens or previews a maliciously crafted .prz file, the buffer overflow occurs during the parsing and rendering operations, allowing an attacker to overwrite adjacent memory locations with malicious code. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking permits data to be written beyond the allocated buffer space. The vulnerability demonstrates characteristics consistent with CWE-787, heap-based buffer overflow, when the overflow impacts heap memory structures during processing.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a remote attack vector that does not require user interaction beyond opening the malicious attachment. This makes it particularly dangerous in enterprise email environments where Lotus Notes is commonly deployed, as users may inadvertently open compromised emails containing the malicious .prz attachments. The exploitability of this vulnerability is further enhanced by the fact that it operates at the application level, bypassing many network-level security controls and requiring minimal user engagement to achieve successful compromise. Attackers could leverage this vulnerability to execute arbitrary code with the privileges of the affected application, potentially leading to complete system compromise, data exfiltration, or establishment of persistent backdoors within the enterprise network.
Security mitigations for CVE-2011-1217 primarily focus on immediate remediation through the installation of IBM Lotus Notes 8.5.2 Fix Pack 3 or subsequent updates that contain the patched kpprzrdr.dll component. Organizations should implement comprehensive email filtering solutions that scan for and quarantine suspicious .prz attachments, particularly those from untrusted sources or that exhibit anomalous file characteristics. Network administrators should also consider implementing application whitelisting policies that restrict execution of known vulnerable components, while monitoring for unusual file processing patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation would likely involve execution of malicious code within the application context, and T1203 for Exploitation for Client Execution, since it specifically targets client-side applications for remote code execution. Organizations should also conduct regular security assessments to identify and remediate similar vulnerabilities in other legacy components that may be vulnerable to similar buffer overflow conditions.