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The git-fastclone.rb script contains insecure file handling practices that can be exploited to perform unauthorized file access and potentially lead to command injection. This vulnerability is exacerbated by the potential for chaining with other vulnerabilities, such as command execution without proper validation.
Assume the following Ruby code is part of the application:
clone_dest = "/tmp/attacker-controlled"
dest_with_dotfiles = Dir.glob("#{clone_dest}/*", File::FNM_DOTMATCH)
dest_with_dotfiles.each do |file|
system("sh #{file}") # This executes the malicious script
end
Execute the Vulnerable Script:
Run the Ruby script or the part of the application where the vulnerable code exists.
The malicious script should execute, demonstrating the command injection vulnerability.
Expected Outcome
When the vulnerable code executes, you should see the output from the malicious script: Malicious code executed
Additionally, if the script contained a harmful command like rm -rf /important/data, it would execute that command, demonstrating the potential severity of the vulnerability.
Impact
Confidentiality: Unauthorized access to sensitive files.
Integrity: Potential file modification leading to corrupted or malicious files.
Availability: Disruption of service by altering or deleting critical files.
Conclusion:
Properly sanitizing and validating file paths, restricting file permissions, and securely handling command execution can significantly reduce the risk of exploitation. Implementing these mitigations will help protect against unauthorized access and potential command injection vulnerabilities.
Mitigation Code Example:
require 'pathname'
# Example of safer file handling with Pathname
def secure_file_open(path, mode)
safe_path = Pathname.new(path).cleanpath
raise "Invalid path" unless safe_path.ascend.all? { |p| p.absolute? }
File.open(safe_path, mode)
end
# Usage of the secure_file_open method
lock_file_name = "/some/lock/file" # This should be derived safely
secure_file_open(lock_file_name, File::RDWR | File::CREAT, 0o644) do |file|
# Perform operations on the file
end
# Example of secure directory traversal prevention
def secure_dir_glob(pattern)
safe_pattern = Pathname.new(pattern).cleanpath.to_s
raise "Invalid pattern" if safe_pattern.include?("..")
Dir.glob(safe_pattern, File::FNM_DOTMATCH)
end
# Usage of the secure_dir_glob method
clone_dest = "/some/clone/dest"
dest_with_dotfiles = secure_dir_glob("#{clone_dest}/*")
The text was updated successfully, but these errors were encountered:
hackergandhi
changed the title
Insecure File Handling Leading to Potential Command Injection Submitted at Last activity
Insecure File Handling Leading to Potential Command Injection
Jun 2, 2024
location: https://github.com/square/git-fastclone/tree/master/lib
Overview of the Vulnerability
The
git-fastclone.rb
script contains insecure file handling practices that can be exploited to perform unauthorized file access and potentially lead to command injection. This vulnerability is exacerbated by the potential for chaining with other vulnerabilities, such as command execution without proper validation.Affected Components
Script: git-fastclone.rb
- Functions:
File.open
Dir.glob
FileUtils.mkdir_p
File.expand_path
Vulnerability Details
1) Insecure File Handling
Issue:
lock_file_name
is not validated, allowing potential unauthorized file access.Issue:
clone_dest
is not sanitized, allowing directory traversal attacks.Issue:
reference_dir
is created without validation, possibly leading to unintended directories.Issue:
hook_command
is expanded without validation, allowing path traversal.2) Potential Command Injection
If an attacker can manipulate file paths and place
malicious
scripts, they might exploit the application's command execution logic.Steps to Reproduce
1) Directory Traversal and File Manipulation
clone_dest
and observe unauthorized file access.clone_dest
to a path containing../../
to traverse directories.Example Code to Reproduce
2) Steps to Reproduce Command Injection
/tmp/attacker-controlled
.malicious.sh
in the directory that will execute arbitrary commands.Detailed Steps
Expected Outcome
Malicious code executed
-rf /important/data
, it would execute that command, demonstrating the potential severity of the vulnerability.Impact
Conclusion:
Properly sanitizing and validating file paths, restricting file permissions, and securely handling command execution can significantly reduce the risk of exploitation. Implementing these mitigations will help protect against unauthorized access and potential command injection vulnerabilities.
Mitigation Code Example:
The text was updated successfully, but these errors were encountered: