CVE-2011-0918 in Lotus Domino
Summary
by MITRE
Stack-based buffer overflow in the NRouter (aka Router) service in IBM Lotus Domino allows remote attackers to execute arbitrary code via long filenames associated with Content-ID and ATTACH:CID headers in attachments in malformed calendar-request e-mail messages, aka SPR KLYH87LKRE.
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Analysis
by VulDB Data Team • 10/14/2021
The vulnerability identified as CVE-2011-0918 represents a critical stack-based buffer overflow within IBM Lotus Domino's NRouter service component. This flaw specifically manifests when processing malformed calendar-request email messages containing specially crafted Content-ID and ATTACH:CID headers in attachment metadata. The vulnerability resides in the router service responsible for handling email routing and processing within the Domino email server environment, making it a core component of the system's email infrastructure. The issue stems from inadequate input validation mechanisms that fail to properly sanitize or limit the length of filename data processed in these specific header fields.
The technical implementation of this vulnerability exploits the fundamental weakness in stack memory management where maliciously constructed filenames exceed the allocated buffer space in memory. When the NRouter service processes calendar-request messages with overly long filenames in the Content-ID and ATTACH:CID headers, the service fails to perform proper bounds checking before copying the filename data into a fixed-size stack buffer. This buffer overflow condition allows remote attackers to overwrite adjacent memory locations including return addresses and control data, effectively enabling arbitrary code execution. The vulnerability specifically targets the router service's handling of email attachments within calendar requests, making it particularly dangerous in environments where calendar integration and email routing are heavily utilized.
The operational impact of this vulnerability is severe and far-reaching across enterprise email environments utilizing IBM Lotus Domino servers. Remote attackers can leverage this flaw to gain unauthorized code execution privileges on affected systems, potentially leading to complete system compromise, data exfiltration, and persistence within the network. The attack vector requires only the ability to send specially crafted email messages to the Domino server, making it particularly dangerous in environments where email is widely used for business communications. The vulnerability affects organizations running IBM Lotus Domino versions prior to the security patch, creating widespread exposure across corporate email infrastructures that rely on this platform for business email services.
Mitigation strategies for CVE-2011-0918 should prioritize immediate implementation of the vendor-provided security patches and updates from IBM. Organizations must also implement network-based restrictions to limit email traffic to the Domino server, particularly filtering calendar request messages and attachments that may contain malicious content. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which is categorized under the broader class of memory safety errors in software development. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1059.007 for command and script interpreter, as successful exploitation would allow attackers to execute arbitrary commands on the compromised system. Security teams should also consider implementing email content filtering rules that detect and block malformed calendar request messages, particularly those containing unusually long filenames in header fields, as an additional defensive measure while awaiting patch deployment.