CVE-2003-1120 in Tectia Server
Summary
by MITRE
Race condition in SSH Tectia Server 4.0.3 and 4.0.4 for Unix, when the password change plugin (ssh-passwd-plugin) is enabled, allows local users to obtain the server s private key.
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Analysis
by VulDB Data Team • 11/19/2024
The vulnerability described in CVE-2003-1120 represents a critical race condition flaw within SSH Tectia Server versions 4.0.3 and 4.0.4 for Unix systems. This issue specifically manifests when the password change plugin ssh-passwd-plugin is enabled, creating a dangerous window of opportunity for local attackers to exploit the system's security mechanisms. The race condition occurs during the execution of password change operations, where concurrent processes or threads can interfere with each other's execution flow, potentially leading to unauthorized access to sensitive system resources.
The technical implementation of this vulnerability stems from improper synchronization mechanisms within the password change plugin functionality. When users attempt to change their passwords through the SSH server, the system creates temporary files or modifies configuration elements that are not adequately protected against concurrent access. This race condition allows a local attacker to exploit the timing window between when the system checks for valid credentials and when it actually updates the password, potentially intercepting or accessing the server's private key during this critical period. The flaw operates at the system call level where file operations and process synchronization fail to maintain atomicity, creating a scenario where multiple processes can access shared resources simultaneously without proper locking mechanisms.
The operational impact of this vulnerability is severe for organizations relying on SSH Tectia Server for secure remote access and authentication. A successful exploitation allows local users to obtain the server's private key, which fundamentally compromises the entire security infrastructure of the system. With access to the private key, attackers can establish unauthorized secure connections to the server, decrypt communications, impersonate legitimate users, and potentially escalate privileges to gain further system access. This vulnerability essentially undermines the core cryptographic foundations that SSH protocols rely upon for secure communications, making it particularly dangerous in environments where server authentication and data integrity are paramount.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-362, which describes race conditions in software systems where multiple threads or processes can access shared resources simultaneously without proper synchronization. The attack vector follows patterns consistent with the ATT&CK technique T1552.001, which involves the exploitation of credentials and keys to gain unauthorized access to systems. Organizations should implement immediate mitigations including disabling the password change plugin when not required, applying the vendor-provided patches, and implementing proper access controls to limit local user privileges. Additionally, system administrators should conduct regular security audits to identify and remediate similar synchronization issues across other network services and applications. The vulnerability highlights the critical importance of proper concurrent programming practices and the need for thorough security testing of authentication mechanisms in server environments, particularly in legacy systems where such race conditions may persist due to insufficient attention to thread safety and resource management during development phases.