CVE-2013-2616 in Mini Magick
Summary
by MITRE
lib/mini_magick.rb in the MiniMagick Gem 1.3.1 for Ruby allows remote attackers to execute arbitrary commands via shell metacharacters in a URL.
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Analysis
by VulDB Data Team • 01/01/2022
The vulnerability identified as CVE-2013-2616 affects the MiniMagick Ruby gem version 1.3.1, specifically within the lib/mini_magick.rb file. This represents a critical command injection flaw that enables remote attackers to execute arbitrary system commands through maliciously crafted URLs. The vulnerability arises from insufficient input validation and improper sanitization of user-supplied data when processing image operations through the gem's interface.
The technical root cause stems from the gem's handling of image URLs that contain shell metacharacters such as semicolons, ampersands, or backticks. When MiniMagick processes these URLs, it fails to properly escape or filter special characters that could be interpreted by the underlying shell, allowing attackers to inject malicious commands. This occurs because the gem directly incorporates user-provided URL parameters into shell commands without adequate sanitization, creating a classic command injection vulnerability. The flaw is categorized under CWE-78 as improper neutralization of special elements used in OS commands, which is a well-documented weakness in software systems.
From an operational perspective, this vulnerability poses significant risks to applications that utilize MiniMagick for image processing tasks. Attackers can leverage this flaw to execute arbitrary code on the server hosting the vulnerable application, potentially leading to complete system compromise. The impact extends beyond simple command execution, as attackers could gain access to sensitive data, modify system configurations, or establish persistent backdoors. The vulnerability is particularly dangerous because it can be exploited remotely without requiring authentication, making it an attractive target for automated attacks. This aligns with ATT&CK technique T1059.001 for command and scripting interpreter, specifically focusing on the execution of system commands through shell injection.
The exploitation of CVE-2013-2616 typically involves crafting a malicious URL containing shell metacharacters that get processed by MiniMagick's image handling functions. When the application processes this URL, the shell commands embedded within the URL parameters are executed with the privileges of the web application, often running as the web server user. This could potentially provide attackers with access to the application's data, network resources, or even escalate privileges to root access depending on the server configuration. Organizations using MiniMagick in production environments are particularly vulnerable, as the gem is commonly used for image processing in web applications, content management systems, and file upload functionalities.
Mitigation strategies for this vulnerability include immediate upgrading to a patched version of the MiniMagick gem, as the maintainers released updates that properly sanitize input parameters. Administrators should also implement proper input validation and sanitization at multiple layers of their applications, ensuring that all user-supplied data is properly escaped before being processed by shell commands. Network-level protections such as web application firewalls can help detect and block malicious requests containing shell metacharacters. Additionally, following secure coding practices that emphasize the principle of least privilege and avoiding direct shell command execution with user input can prevent similar vulnerabilities from occurring in other components. The vulnerability serves as a reminder of the critical importance of proper input validation and the dangerous consequences of insecure command construction in software development.