CVE-2008-4729 in Exceed
Summary
by MITRE
Stack-based buffer overflow in Hummingbird.XWebHostCtrl.1 ActiveX control (hclxweb.dll) in Hummingbird Xweb ActiveX Control 13.0 and earlier allows remote attackers to execute arbitrary code via a long PlainTextPassword property. NOTE: code execution might not be possible in 13.0.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 02/28/2025
The vulnerability identified as CVE-2008-4729 represents a critical stack-based buffer overflow affecting the Hummingbird Xweb ActiveX control version 13.0 and earlier. This flaw exists within the hclxweb.dll component that implements the Hummingbird.XWebHostCtrl.1 ActiveX control, creating a significant security risk for systems running affected software. The vulnerability specifically manifests when processing the PlainTextPassword property, which serves as the attack vector for remote code execution. The buffer overflow occurs due to insufficient input validation and bounds checking within the ActiveX control's implementation, allowing attackers to overwrite adjacent memory locations on the stack.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite stack data structures. The flaw operates by accepting an overly long string value for the PlainTextPassword property, causing the buffer allocated for this parameter to be exceeded. This overflow can potentially overwrite return addresses, function pointers, or other critical stack data, enabling attackers to redirect program execution flow. The vulnerability's remote exploitability means that attackers can trigger the condition through web-based attacks without requiring local system access, making it particularly dangerous in web browser environments where ActiveX controls are executed.
From an operational impact perspective, this vulnerability creates a severe threat landscape for organizations using the affected Hummingbird Xweb ActiveX control. The potential for arbitrary code execution provides attackers with complete system compromise capabilities, including privilege escalation and persistent access. The vulnerability's exploitation could lead to data breaches, system infiltration, and lateral movement within network environments. Given that ActiveX controls are typically executed with the privileges of the user running the browser, successful exploitation could result in complete system compromise. The fact that code execution might not be possible in version 13.0 suggests that the vulnerability was partially addressed in that release, though the earlier versions remain highly susceptible to attack.
The attack surface for this vulnerability extends to any system running Internet Explorer with the affected ActiveX control installed, particularly in corporate environments where such controls might be deployed for legacy application support. The vulnerability's presence in web-based attack scenarios aligns with ATT&CK technique T1190, which covers exploitation of web applications for code execution. Organizations should consider implementing browser security measures, such as ActiveX control restrictions, enhanced sandboxing, and regular security updates. The recommended mitigations include immediate patching of affected systems, disabling the problematic ActiveX control in web browsers, and implementing network-based protections such as intrusion detection systems. Additionally, security teams should conduct comprehensive vulnerability assessments to identify all instances of the affected ActiveX control within their environments, as the vulnerability could be present in various legacy applications or system configurations that utilize the Hummingbird Xweb components.