CVE-2011-5122 in Internet Security
Summary
by MITRE
The Antivirus component in Comodo Internet Security before 5.3.175888.1227 allows remote attackers to cause a denial of service (application crash) via a crafted compressed file.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/11/2018
The vulnerability identified as CVE-2011-5122 affects the antivirus component of Comodo Internet Security versions prior to 5.3.175888.1227, representing a significant security weakness that could be exploited by remote attackers to disrupt system operations. This flaw specifically targets the decompression handling mechanism within the antivirus engine, where improper validation of compressed file structures leads to application instability. The vulnerability falls under the category of improper input validation as defined by CWE-20, where the system fails to properly validate or sanitize input data before processing it. The affected Comodo Internet Security product operates as a comprehensive endpoint protection solution that includes real-time monitoring, behavior detection, and automated threat response capabilities. When a malicious actor crafts a specially designed compressed file, the antivirus engine's decompression routine encounters malformed or unexpected data structures that trigger memory corruption or stack overflow conditions, ultimately leading to application termination.
The operational impact of this vulnerability extends beyond simple service disruption, as it represents a potential vector for more sophisticated attacks that could leverage the denial of service condition to mask other malicious activities or create opportunities for privilege escalation. Attackers could exploit this weakness to repeatedly crash the antivirus service, effectively disabling critical protection mechanisms and leaving systems vulnerable to other threats. The vulnerability's remote exploitation capability means that no local access is required for successful attack, making it particularly dangerous in networked environments where multiple systems may be simultaneously targeted. From an attack chain perspective, this vulnerability aligns with ATT&CK technique T1499.004 which covers "Toggle File Execution Flags" and represents a foundational step in compromising endpoint security. The affected Comodo product's antivirus engine processes compressed files as part of its threat detection routine, particularly when examining archives, compressed executables, or files that may contain embedded threats. This processing occurs without adequate bounds checking or error handling for malformed compressed data structures, creating an exploitable condition that directly impacts the application's stability and reliability.
Mitigation strategies for this vulnerability should prioritize immediate patching of Comodo Internet Security to version 5.3.175888.1227 or later, which contains the necessary fixes to properly validate compressed file structures before decompression. Organizations should implement network segmentation and access controls to limit exposure of vulnerable systems, while also monitoring for unusual application crash patterns that might indicate exploitation attempts. Security teams should establish incident response procedures specifically addressing antivirus service disruptions and maintain backup security measures to ensure continuous protection during patch deployment. The fix likely involves implementing proper input validation routines that check compressed file headers and structure integrity before processing, along with enhanced error handling that prevents malformed data from causing memory corruption. System administrators should also consider deploying additional monitoring solutions that can detect abnormal application behavior or service termination patterns that might indicate exploitation of similar input validation vulnerabilities. Organizations using Comodo Internet Security should conduct thorough vulnerability assessments to identify other potential weaknesses in their endpoint protection stack and ensure that all security components maintain robust input validation mechanisms. The vulnerability demonstrates the critical importance of proper input sanitization in security software and highlights how flaws in seemingly routine operations like file decompression can lead to significant operational disruptions and security gaps.