CVE-2006-6837 in Iso Wincmd
Summary
by MITRE
Multiple stack-based buffer overflows in the (1) LoadTree, (2) ReadHeader, and (3) LoadXBOXTree functions in the ISO (iso_wincmd) plugin 1.7.3.3 and earlier for Total Commander allow user-assisted remote attackers to execute arbitrary code via a long pathname in an ISO image.
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Analysis
by VulDB Data Team • 10/02/2017
The vulnerability identified as CVE-2006-6837 represents a critical security flaw affecting the iso_wincmd plugin version 1.7.3.3 and earlier within Total Commander software. This issue manifests through three distinct functions - LoadTree, ReadHeader, and LoadXBOXTree - all of which are susceptible to stack-based buffer overflow conditions when processing ISO image files. The vulnerability operates under the premise that an attacker can craft malicious ISO images containing excessively long pathnames that trigger memory corruption during the parsing process. These buffer overflows occur in the plugin's handling of compressed filesystem structures, specifically when the software attempts to load and process directory trees from ISO containers.
The technical implementation of this vulnerability leverages the fundamental principle of stack memory corruption where input data exceeding the allocated buffer space causes adjacent memory locations to be overwritten. When Total Commander processes an ISO image through the affected plugin, the LoadTree function attempts to parse directory structures and store pathname information in stack buffers that are insufficiently sized for handling extended pathnames. Similarly, ReadHeader and LoadXBOXTree functions exhibit the same weakness when processing header information and xbox-specific tree structures respectively. The flaw is classified as a stack-based buffer overflow under CWE-121, which specifically addresses the condition where insufficient bounds checking allows attackers to overwrite stack data structures. This vulnerability directly enables arbitrary code execution under the attacker's control, making it particularly dangerous for remote exploitation scenarios.
The operational impact of CVE-2006-6837 extends beyond simple local privilege escalation as it provides remote attackers with a mechanism to execute arbitrary code on systems running vulnerable versions of Total Commander. The user-assisted nature of the attack means that victims must actively choose to open or process the malicious ISO file, typically through a file browser or archive extraction process. However, the attack vector remains significant since users often trust ISO images from unverified sources, especially in environments where software distribution occurs through network shares or email attachments. The vulnerability affects systems where Total Commander is installed with the iso_wincmd plugin, which is commonly found in Windows environments where file management tools are prevalent. The attack chain typically involves crafting a malicious ISO image containing overly long pathnames that trigger the buffer overflow during the loading process, potentially allowing attackers to inject and execute malicious code with the privileges of the user running Total Commander.
Mitigation strategies for CVE-2006-6837 require immediate patching of the affected Total Commander plugin to version 1.7.4 or later, which contains the necessary buffer size adjustments and input validation fixes. System administrators should also implement strict file access controls and sandboxing mechanisms to limit the impact of potential exploitation attempts. Network security measures including content filtering and endpoint protection should be deployed to prevent the delivery of malicious ISO files to user systems. The vulnerability demonstrates the importance of input validation and buffer management practices as outlined in the OWASP Top 10 security principles, particularly addressing injection flaws and improper error handling. Additionally, organizations should consider implementing principle of least privilege access controls and regular security audits to identify and remediate similar vulnerabilities in legacy software components. The ATT&CK framework categorizes this vulnerability under T1059 for command and scripting interpreter, as successful exploitation would likely involve execution of malicious code through the compromised Total Commander process, potentially leading to further lateral movement within affected networks.