CVE-2005-3345 in rssh
Summary
by MITRE
rssh 2.0.0 through 2.2.3 allows local users to bypass access restrictions and gain root privileges by using the rssh_chroot_helper command to chroot to an external directory.
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Analysis
by VulDB Data Team • 06/29/2025
The vulnerability described in CVE-2005-3345 represents a critical privilege escalation flaw within the rssh (restricted shell) utility version 2.0.0 through 2.2.3. This issue stems from improper access control mechanisms within the rssh_chroot_helper command, which is designed to facilitate chroot operations for restricted user environments. The flaw allows local attackers to manipulate the chroot process in a manner that bypasses intended security boundaries, ultimately enabling them to escalate privileges to the root level. This vulnerability directly impacts systems where rssh is configured to provide restricted shell access to users while maintaining security through chroot jails.
The technical implementation of this vulnerability exploits a design flaw in how the rssh_chroot_helper command handles directory traversal and chroot operations. When the helper command is invoked, it fails to properly validate or restrict the target directory path that users can specify during the chroot process. This allows malicious users to provide carefully crafted directory paths that point to external locations outside the intended restricted environment. The flaw essentially enables attackers to escape the chroot jail by creating symbolic links or by specifying directory paths that circumvent the intended confinement mechanisms. The vulnerability is particularly dangerous because it operates at the system level where the helper command typically runs with elevated privileges, making it a prime target for privilege escalation attacks.
From an operational perspective, this vulnerability creates significant security implications for systems that rely on rssh for user access control and privilege management. Organizations using rssh for restricted shell access are exposed to potential full system compromise, as local attackers can leverage this flaw to gain root access without requiring additional exploitation vectors. The impact extends beyond simple privilege escalation since the compromised system can then be used as a foothold for further attacks, lateral movement, and data exfiltration. Systems where rssh is configured to provide access to sensitive resources, administrative accounts, or critical infrastructure components face particularly severe risks from this vulnerability.
Security mitigation strategies for CVE-2005-3345 should prioritize immediate patching of affected rssh versions to 2.2.4 or later, which contains the necessary fixes for the chroot helper command validation. Administrators should also implement strict directory access controls and monitor for unauthorized chroot operations within system logs. The vulnerability aligns with CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-787 (Out-of-bounds Write) categories, demonstrating how improper path validation can lead to privilege escalation. Organizations should consider implementing additional security controls such as mandatory access controls, regular privilege audits, and monitoring for suspicious chroot activities. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting T1068 (Local Port Forwarding) and T1548.1 (Abuse Elevation Control Mechanism) tactics that attackers use to gain elevated system privileges through flawed access control mechanisms.