CVE-2005-4511 in TN3270 Resource Gateway
Summary
by MITRE
Format string vulnerability in TN3270 Resource Gateway 1.1.0 allows local users to cause a denial of service and possibly execute arbitrary code via format string specifiers in syslog function calls.
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Analysis
by VulDB Data Team • 08/06/2017
The TN3270 Resource Gateway version 1.1.0 contains a critical format string vulnerability that stems from improper handling of user-supplied input within syslog function calls. This vulnerability exists in the gateway's logging mechanism where format string specifiers are directly processed without adequate validation or sanitization, creating a dangerous attack surface for local users who can manipulate these inputs to trigger unintended behavior.
The technical flaw manifests when the application processes user-provided data through syslog functions that expect format strings. When malicious input containing format specifiers such as %s, %d, or %x is passed to these functions, the system interprets these characters as instructions for formatting output rather than literal text. This misinterpretation allows attackers to read arbitrary memory locations, manipulate program flow, and potentially execute arbitrary code with the privileges of the affected process. The vulnerability is classified under CWE-134 as "Use of Externally-Controlled Format String" which represents a well-documented class of vulnerabilities that have been consistently exploited in various software systems.
Local users can exploit this vulnerability to cause a denial of service by triggering segmentation faults or program crashes through malformed format string arguments. However, the more severe implications arise when attackers can leverage this weakness to execute arbitrary code on the target system. The privilege escalation potential depends on the execution context of the TN3270 Resource Gateway process, which typically runs with elevated privileges to manage network connections and terminal emulation services. This makes the vulnerability particularly dangerous as successful exploitation could provide attackers with complete control over the affected system.
The operational impact of this vulnerability extends beyond immediate service disruption to encompass potential data compromise and system infiltration. Organizations utilizing TN3270 Resource Gateway in production environments face significant risk from local attackers who may use this vulnerability to establish persistent access or escalate privileges within their network infrastructure. The vulnerability's local nature means that attackers need physical or account access to the system, but this requirement is often met through various social engineering or privilege escalation techniques that attackers frequently employ.
Mitigation strategies should focus on immediate patching of the affected software to address the root cause of the vulnerability. Organizations must ensure that all instances of TN3270 Resource Gateway 1.1.0 are updated to versions that properly validate and sanitize input before processing through logging functions. Additionally, implementing proper input validation and using secure coding practices that prevent format string vulnerabilities should be enforced throughout the organization's software development lifecycle. Network segmentation and privilege separation measures can help limit the potential impact even if exploitation occurs, while monitoring systems should be configured to detect unusual logging activity that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1499.004 for Endpoint Denial of Service, representing both execution and denial of service attack vectors that require careful monitoring and protection.