CVE-2000-1178 in Joe
Summary
by MITRE
Joe text editor follows symbolic links when creating a rescue copy called DEADJOE during an abnormal exit, which allows local users to overwrite the files of other users whose joe session crashes.
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Analysis
by VulDB Data Team • 05/02/2019
The vulnerability described in CVE-2000-1178 represents a critical security flaw in the joe text editor that stems from improper handling of symbolic links during emergency file recovery operations. This issue specifically manifests when the joe editor experiences an abnormal termination, prompting it to create a rescue copy named DEADJOE in the same directory as the original file. The flaw occurs because the editor does not properly validate or sanitize the symbolic link resolution process, allowing malicious users to exploit this behavior for unauthorized file modification.
The technical implementation of this vulnerability involves the joe editor's failure to properly manage file system permissions and symbolic link resolution during crash recovery scenarios. When a user session crashes, the editor attempts to create a rescue file with a predictable name pattern, but it does not verify whether the target directory contains symbolic links that could redirect the file creation to an unintended location. This behavior creates a race condition where an attacker can manipulate the file system to ensure that the DEADJOE file is created in a location accessible to other users, thereby enabling them to overwrite or modify files belonging to different system accounts.
From an operational impact perspective, this vulnerability presents a significant risk to multi-user systems where multiple users share common directories or workspaces. The exploit requires local system access and knowledge of the target user's session, but once executed, it allows for privilege escalation through file system manipulation. The vulnerability aligns with CWE-59, which describes improper link resolution without a full path, and represents a classic example of a race condition attack vector. Attackers can leverage this flaw to gain unauthorized access to sensitive files, potentially compromising system integrity and confidentiality.
The security implications extend beyond simple file overwriting, as this vulnerability can be exploited to create persistent backdoors or to modify critical system files that are part of the user's session or the editor's configuration. The ATT&CK framework categorizes this as a privilege escalation technique through file system manipulation, where attackers exploit weaknesses in application behavior to gain elevated privileges. The vulnerability also demonstrates poor security practices in file handling, particularly in the context of emergency recovery mechanisms that should be designed with security as a primary consideration.
Mitigation strategies for CVE-2000-1178 should focus on both immediate system hardening and long-term architectural improvements. System administrators should ensure that the joe editor is updated to versions that properly handle symbolic link resolution during emergency operations, or consider replacing it with more secure text editors that implement proper file system validation. The recommended approach includes implementing proper directory permissions, disabling the automatic rescue copy feature when running in multi-user environments, and establishing monitoring for unusual file creation patterns in shared directories. Additionally, users should be educated about the risks of running text editors with elevated privileges or in shared workspaces, and organizations should implement regular security audits to identify similar vulnerabilities in other system components that may exhibit similar behaviors during crash recovery operations.