CVE-2011-10016 in Netzip Classic
Summary
by MITRE • 08/14/2025
Real Networks Netzip Classic version 7.5.1.86 is vulnerable to a stack-based buffer overflow when parsing a specially crafted ZIP archive. The vulnerability is triggered when the application attempts to process a file name within the archive that exceeds the expected buffer size. Exploitation allows arbitrary code execution under the context of the victim user when the ZIP file is opened.
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Analysis
by VulDB Data Team • 08/15/2025
The vulnerability identified as CVE-2011-10016 represents a critical stack-based buffer overflow flaw in Real Networks Netzip Classic version 7.5.1.86 that demonstrates the persistent risks associated with legacy archive processing software. This vulnerability falls under the Common Weakness Enumeration category CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw manifests when the application processes specially crafted ZIP archives containing file names that exceed the allocated buffer space, creating a scenario where attacker-controlled data can overwrite critical stack memory components including return addresses and function pointers.
The technical exploitation mechanism relies on the application's insufficient input validation during ZIP archive parsing operations, particularly when handling file names within compressed archives. When Netzip Classic encounters a file name exceeding the predefined buffer limits, the application fails to properly terminate or truncate the input data before copying it to the stack buffer. This condition creates a predictable memory corruption scenario where an attacker can carefully construct a malicious ZIP archive containing oversized file names that overwrite the stack frame. The vulnerability's exploitation potential is amplified by the fact that the application executes under the privileges of the victim user, meaning successful exploitation results in arbitrary code execution with the same user context, potentially enabling privilege escalation or system compromise.
The operational impact of this vulnerability extends beyond simple code execution, as it represents a significant attack vector for remote code execution in environments where users may unknowingly open malicious ZIP files. The vulnerability's trigger mechanism is particularly concerning because ZIP file handling is a common user activity across multiple platforms and applications, making the attack surface broad and accessible. Security analysts have identified that this flaw aligns with ATT&CK technique T1068, which involves exploiting legitimate credentials and system access to execute malicious code. The vulnerability's persistence in older software versions demonstrates the ongoing challenges organizations face with legacy systems that receive limited security updates, creating sustained exposure windows for attackers who can leverage these known weaknesses.
Organizations should implement immediate mitigation strategies including disabling automatic ZIP file processing, implementing strict file extension filtering, and deploying application whitelisting controls to prevent execution of vulnerable applications. The recommended remediation involves upgrading to patched versions of Netzip Classic or transitioning to more modern and actively maintained archive processing solutions. Security teams should also consider network-based intrusion detection system rules to identify and block known malicious ZIP file patterns, while conducting comprehensive vulnerability assessments to identify other legacy applications that may present similar stack overflow vulnerabilities. The incident underscores the critical importance of maintaining up-to-date security patches and implementing robust software inventory management to prevent exploitation of known vulnerabilities in outdated applications.