CVE-2011-2947 in RealPlayer
Summary
by MITRE
Cross-zone scripting vulnerability in the RealPlayer ActiveX control in RealNetworks RealPlayer 11.0 through 11.1 and 14.0.0 through 14.0.5 and RealPlayer SP 1.0 through 1.1.5 allows remote attackers to inject arbitrary web script or HTML in the Local Zone via a local HTML document.
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Analysis
by VulDB Data Team • 11/18/2021
The CVE-2011-2947 vulnerability represents a critical cross-zone scripting flaw in RealNetworks RealPlayer ActiveX control versions 11.0 through 11.1 and 14.0.0 through 14.0.5, along with RealPlayer SP 1.0 through 1.1.5. This vulnerability resides within the browser zone isolation mechanisms that are fundamental to ActiveX security models, specifically targeting the boundary between the Internet Zone and Local Machine Zone. The flaw allows attackers to bypass security restrictions that normally prevent code execution from local files within the more trusted local zone. The vulnerability is classified under CWE-94, which describes "Improper Control of Generation of Code" and aligns with ATT&CK technique T1059.001 for command and scripting interpreter execution.
The technical implementation of this vulnerability exploits the ActiveX control's improper handling of local HTML documents that contain malicious script code. When a user opens a specially crafted local HTML file that references the vulnerable RealPlayer ActiveX control, the control fails to properly validate or sanitize input from local sources. This allows arbitrary web script or HTML code to be injected and executed within the Local Zone context, effectively elevating privileges and bypassing the security boundaries that separate local and remote content execution. The vulnerability specifically affects the ActiveX control's zone handling mechanism, which should normally prevent local files from executing code that could access restricted resources or perform malicious actions.
The operational impact of CVE-2011-2947 is significant as it enables remote attackers to leverage local HTML documents as attack vectors, potentially allowing for privilege escalation, data theft, or system compromise. Attackers can craft malicious local HTML files that, when opened by an unsuspecting user, automatically trigger the vulnerable RealPlayer ActiveX control and execute malicious code within the local zone. This creates a dangerous scenario where a remote attacker can potentially exploit a user's local system through a local file, bypassing traditional network-based security controls. The vulnerability can be particularly dangerous in enterprise environments where users may have elevated privileges or access to sensitive systems.
Mitigation strategies for CVE-2011-2947 should focus on immediate remediation through patching the vulnerable RealPlayer versions, which was the primary solution provided by RealNetworks. Organizations should implement strict ActiveX control management policies, including disabling unnecessary ActiveX controls and implementing proper zone configuration settings. The vulnerability demonstrates the importance of proper zone isolation in ActiveX security models and highlights the need for comprehensive security policies that address both local and remote execution contexts. Additionally, user education regarding the risks of opening untrusted local files and implementing network-based security controls such as web application firewalls can provide additional defense layers against exploitation attempts.