CVE-2014-4996 in VladTheEnterprising Gem
Summary
by MITRE
lib/vlad/dba/mysql.rb in the VladTheEnterprising gem 0.2 for Ruby allows local users to write to arbitrary files via a symlink attack on /tmp/my.cnf.#{target_host}.
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Analysis
by VulDB Data Team • 01/29/2021
The vulnerability identified as CVE-2014-4996 resides within the VladTheEnterprising gem version 0.2 for Ruby, specifically in the file lib/vlad/dba/mysql.rb. This flaw represents a classic symlink attack vector that enables local users to manipulate file operations through improper temporary file handling. The vulnerability occurs when the gem creates a temporary configuration file at /tmp/my.cnf.#{target_host} without adequate security measures to prevent symbolic link manipulation. The issue stems from the gem's failure to validate or sanitize the temporary file path before creating or writing to it, creating an opportunity for privilege escalation and unauthorized file modification.
The technical implementation of this vulnerability involves the gem's reliance on a predictable temporary file location that does not properly account for symbolic link attacks. When the application executes and attempts to write to /tmp/my.cnf.#{target_host}, an attacker who controls the target host name can manipulate the path to point to a symbolic link that resolves to a sensitive system file or directory. This allows the attacker to write arbitrary content to locations they would normally not have permission to modify. The flaw aligns with CWE-377 which addresses insecure temporary file creation and CWE-367 which covers the insecure handling of symbolic links during file operations. The vulnerability can be exploited through a combination of local privilege escalation techniques and path manipulation, making it particularly dangerous in multi-user environments where attackers might attempt to gain elevated privileges.
The operational impact of this vulnerability extends beyond simple file modification capabilities and represents a significant security risk for systems running vulnerable versions of the VladTheEnterprising gem. Attackers can leverage this flaw to overwrite critical system configuration files, inject malicious content into sensitive locations, or establish persistent access mechanisms. The vulnerability particularly affects environments where the gem is used for database administration tasks and where local users might have access to the system but lack administrative privileges. The attack surface is broadened by the fact that the vulnerability can be triggered through legitimate database administration operations, making detection more challenging. This weakness can potentially enable attackers to compromise entire database environments or use the compromised system as a stepping stone for further attacks within the network infrastructure.
Mitigation strategies for CVE-2014-4996 should focus on immediate remediation through version updates and proper temporary file handling practices. The primary solution involves upgrading to a patched version of the VladTheEnterprising gem that properly handles temporary file creation and validates file paths before operations. Organizations should implement proper file permissions and ensure that temporary directories have restricted access permissions to prevent symlink attacks. Security controls should include validating that temporary files are created with secure permissions and using atomic file creation techniques that prevent race conditions. Additionally, system administrators should monitor for unauthorized access to temporary directories and implement proper input validation for all parameters used in file path construction. The vulnerability demonstrates the importance of following secure coding practices as outlined in the OWASP Secure Coding Practices and aligns with ATT&CK technique T1059 for executing malicious code through compromised system utilities and T1548 for privilege escalation through file system manipulation.