CVE-2007-6435 in GroupWise
Summary
by MITRE
Stack-based buffer overflow in Novell GroupWise before 6.5.7, when HTML preview of e-mail is enabled, allows user-assisted remote attackers to execute arbitrary code via a long SRC attribute in an IMG element when forwarding or replying to a crafted e-mail.
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Analysis
by VulDB Data Team • 09/13/2018
The vulnerability identified as CVE-2007-6435 represents a critical stack-based buffer overflow flaw in Novell GroupWise email client software prior to version 6.5.7. This vulnerability specifically manifests when the HTML preview feature is enabled, creating a dangerous condition that can be exploited by remote attackers through carefully crafted email messages. The flaw occurs within the processing of HTML content, particularly when handling the SRC attribute of IMG elements during email forwarding or replying operations, making it a user-assisted remote code execution vulnerability that requires minimal user interaction to trigger.
The technical mechanism behind this vulnerability involves the improper handling of input data within the GroupWise email client's HTML rendering engine. When an email containing a maliciously crafted IMG element with an excessively long SRC attribute is processed, the application fails to properly validate or limit the length of this attribute before copying it into a fixed-size stack buffer. This classic buffer overflow condition allows an attacker to overwrite adjacent memory locations, potentially including return addresses and control data, which can be manipulated to redirect program execution flow. The vulnerability is classified as CWE-121 Stack-based Buffer Overflow, which falls under the broader category of memory safety issues that have historically been a primary attack vector for exploitation.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with the capability to gain unauthorized control over affected systems. When a user processes a crafted email message through the GroupWise client with HTML preview enabled, the attacker can potentially execute arbitrary code with the privileges of the user running the application. This creates a significant risk for enterprise environments where GroupWise is widely deployed, as successful exploitation could lead to complete system compromise, data exfiltration, or lateral movement within the network. The vulnerability's user-assisted nature means that the attack requires a user to interact with the malicious email, but this interaction is minimal and can be accomplished through social engineering tactics.
Security professionals should note that this vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, as exploitation typically involves executing malicious code within the target environment. The remediation strategy for this vulnerability involves immediate deployment of Novell GroupWise version 6.5.7 or later, which includes proper input validation and buffer size limitations for HTML attribute processing. Organizations should also implement email filtering rules that block or sanitize HTML content from untrusted sources, disable HTML preview functionality for sensitive users, and conduct regular security assessments of email client configurations to prevent similar vulnerabilities from being exploited in other email platforms. Additionally, network segmentation and monitoring for suspicious email traffic can help detect potential exploitation attempts and reduce the overall attack surface for this class of vulnerability.