CVE-2007-2856 in PowerTCP ZIP Compression
Summary
by MITRE
Buffer overflow in the Dart Communications PowerTCP ZIP Compression ActiveX control in DartZip.dll 1.8.5.3, when Internet Explorer 6 is used, allows user-assisted remote attackers to execute arbitrary code via a long first argument to the QuickZip function, a related issue to CVE-2007-2855.
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Analysis
by VulDB Data Team • 10/19/2017
The vulnerability identified as CVE-2007-2856 represents a critical buffer overflow flaw within the Dart Communications PowerTCP ZIP Compression ActiveX control, specifically affecting the DartZip.dll component version 1.8.5.3. This vulnerability exists within the context of Internet Explorer 6 environments and demonstrates a classic example of unsafe buffer handling in Windows-based ActiveX controls that have been widely deployed across enterprise networks. The flaw is particularly concerning as it leverages the trust model inherent to ActiveX controls, where browser environments automatically grant execution privileges to trusted components, creating an attack surface that can be exploited by remote adversaries.
The technical implementation of this vulnerability occurs through the QuickZip function within the DartZip.dll library, where the first argument parameter fails to properly validate input length before copying data into a fixed-size buffer. This inadequate bounds checking creates a condition where an attacker can provide a maliciously crafted string exceeding the allocated buffer space, resulting in memory corruption that can be leveraged to overwrite adjacent memory locations including return addresses and executable code segments. The vulnerability manifests as a classic stack-based buffer overflow, where the overflow propagates through the call stack and can be manipulated to redirect program execution flow to attacker-controlled code.
From an operational perspective, this vulnerability presents a severe risk to enterprise environments where Internet Explorer 6 remains in use, particularly in legacy systems that have not undergone modernization efforts. The user-assisted nature of the attack means that exploitation typically requires social engineering to convince a user to visit a malicious webpage or open a specially crafted document containing the vulnerable ActiveX control. The attack vector through web browsers exploits the trust relationship between the browser and ActiveX controls, allowing attackers to execute arbitrary code with the privileges of the user running the vulnerable application. This vulnerability directly aligns with attack patterns documented in the attack technique framework, specifically relating to technique T1203 for Exploitation for Client Execution and T1059 for Command and Scripting Interpreter.
The impact of this vulnerability extends beyond simple code execution, as it can potentially enable full system compromise when combined with other attack techniques. The buffer overflow can be exploited to bypass security mechanisms such as DEP (Data Execution Prevention) and ASLR (Address Space Layout Randomization) through various exploitation methods including return-oriented programming (ROP) chains. Organizations utilizing this vulnerable ActiveX control in their environments face significant risk of unauthorized access, data exfiltration, and potential lateral movement within their network infrastructure. This vulnerability exemplifies the dangers of legacy ActiveX controls in modern security environments and demonstrates why organizations should maintain strict controls over ActiveX deployment and regularly audit their browser configurations.
Mitigation strategies for CVE-2007-2856 should include immediate removal or disabling of the vulnerable DartZip.dll component from affected systems, particularly in Internet Explorer 6 environments where the vulnerability is most prevalent. Organizations should implement browser hardening measures such as disabling ActiveX controls in Internet Explorer or restricting ActiveX installation through Group Policy settings. The implementation of security patches and updates should be prioritized, with the vulnerable Dart Communications PowerTCP ZIP Compression ActiveX control being replaced with modern, secure alternatives that do not exhibit buffer overflow vulnerabilities. Additionally, network-based intrusion detection systems should be configured to monitor for exploitation attempts targeting this specific vulnerability, and regular security assessments should be conducted to identify and remediate similar issues in other ActiveX controls and legacy software components.
This vulnerability serves as a historical example of how legacy ActiveX controls can introduce persistent security risks into enterprise environments, with implications that extend to modern security frameworks and threat modeling approaches. The vulnerability's classification under CWE-121 (Stack-based Buffer Overflow) and its relationship to CVE-2007-2855 demonstrates the interconnected nature of software vulnerabilities in legacy components and the importance of maintaining comprehensive vulnerability management programs that address both current and historical security issues. Organizations should treat this vulnerability as representative of broader security challenges associated with maintaining legacy software systems and the critical importance of implementing comprehensive software lifecycle management practices that include regular security assessments and timely updates.