CVE-2005-1853 in gopher client
Summary
by MITRE
gopher.c in the gopher client 3.0.5 does not properly create temporary files which allows local users to gain privileges.
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Analysis
by VulDB Data Team • 03/30/2025
The vulnerability described in CVE-2005-1853 affects the gopher client version 3.0.5 where the gopher.c component fails to properly create temporary files, creating a privilege escalation opportunity for local attackers. This issue stems from insecure temporary file creation practices that can be exploited to manipulate file permissions and gain elevated system privileges. The gopher client, which is used to retrieve resources from gopher servers, typically operates with elevated privileges during certain operations, making this vulnerability particularly dangerous for local users who can exploit the flawed temporary file handling mechanism.
The technical flaw manifests in the improper creation of temporary files within the gopher client application, specifically within the gopher.c source file. When the client creates temporary files, it does not implement proper security measures such as using secure temporary file creation functions or setting appropriate file permissions. This insecure approach allows local users to predict temporary file names or manipulate the file creation process to replace legitimate temporary files with malicious ones. The vulnerability is categorized under CWE-377 as insecure temporary file creation, which directly relates to the lack of proper security controls during temporary file generation. Attackers can exploit this by creating symbolic links or by timing their actions to overwrite temporary files with malicious content, potentially leading to privilege escalation.
The operational impact of this vulnerability extends beyond simple local privilege escalation, as it can enable attackers to gain root access or elevated privileges within the system. The gopher client typically runs with higher privileges than regular user processes, making successful exploitation particularly damaging. Once an attacker gains elevated privileges through this vulnerability, they can modify system files, install malware, or establish persistent access to the compromised system. This vulnerability particularly affects systems where the gopher client is installed with setuid permissions, as it provides the necessary conditions for privilege escalation to occur. The attack vector is primarily local, meaning that the attacker must already have access to the system to exploit this vulnerability, but the consequences can be severe.
Mitigation strategies for this vulnerability include updating to a patched version of the gopher client where temporary file creation is properly implemented with secure practices. System administrators should ensure that all instances of the gopher client are updated to versions that address the insecure temporary file handling. The recommended approach involves implementing proper temporary file creation using secure functions such as mkstemp() or similar secure APIs that guarantee unique file names and appropriate permissions. Additionally, systems should be configured to run the gopher client without setuid privileges when possible, reducing the potential impact of successful exploitation. Security monitoring should include detection of suspicious temporary file creation patterns and unusual file permission changes. This vulnerability demonstrates the importance of secure coding practices and proper temporary file handling, aligning with the principles outlined in the MITRE ATT&CK framework under privilege escalation techniques. Organizations should conduct regular security assessments to identify and remediate similar insecure temporary file creation patterns in other applications. The vulnerability also highlights the need for comprehensive input validation and secure file handling practices as recommended by industry standards and security frameworks.