CVE-2018-19290 in Budabot
Summary
by MITRE
In modules/HELPBOT_MODULE in Budabot 0.6 through 4.0, lax syntax validation allows remote attackers to perform a command injection attack against the PHP daemon with a crafted command, resulting in a denial of service or possibly unspecified other impact, as demonstrated by the "!calc 5 x 5" command. In versions before 3.0, modules/HELPBOT_MODULE/calc.php has the vulnerable code; in 3.0 and above, modules/HELPBOT_MODULE/HelpbotController.class.php has the vulnerable code.
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Analysis
by VulDB Data Team • 07/01/2024
The vulnerability identified as CVE-2018-19290 resides within the HELPBOT_MODULE of Budabot software versions 0.6 through 4.0, representing a critical command injection flaw that fundamentally undermines the application's security posture. This vulnerability manifests due to insufficient input validation mechanisms within the command processing pipeline, specifically affecting the calculation module that handles user commands. The flaw allows remote attackers to inject malicious commands through seemingly innocuous inputs, creating a pathway for arbitrary code execution that can compromise the entire PHP daemon process.
The technical implementation of this vulnerability stems from inadequate sanitization of user-provided input within the HelpbotController.class.php file in versions 3.0 and above, or the calc.php file in versions prior to 3.0. The system fails to properly validate or escape command syntax before processing, enabling attackers to craft payloads that bypass normal input restrictions. When the system processes commands like "!calc 5 x 5", it does not adequately separate user input from executable code, allowing malicious commands to be interpreted and executed by the underlying PHP engine. This represents a classic command injection vulnerability categorized under CWE-77, which specifically addresses improper neutralization of special elements used in commands.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, potentially enabling full system compromise through unauthorized code execution. Attackers can leverage this flaw to execute arbitrary commands on the affected system, potentially gaining access to sensitive data, modifying system configurations, or establishing persistent backdoors. The vulnerability's remote exploitation capability means that attackers do not require physical access or local privileges to exploit the flaw, making it particularly dangerous in networked environments where the PHP daemon may be exposed to untrusted users. The demonstrated proof of concept using the calculator module illustrates how seemingly benign functionality can be weaponized to create serious security breaches.
Mitigation strategies for CVE-2018-19290 require immediate implementation of input validation and sanitization measures throughout the affected codebase. System administrators should upgrade to versions of Budabot that have addressed this vulnerability, typically versions 4.1 or later where proper command validation has been implemented. The recommended approach involves implementing strict input filtering that prevents special characters and command delimiters from being processed as executable code. Additionally, the principle of least privilege should be enforced by running the PHP daemon with minimal required permissions and implementing proper output encoding to prevent command execution. Organizations should also consider implementing network segmentation and monitoring solutions to detect unusual command execution patterns that may indicate exploitation attempts. The vulnerability's classification under ATT&CK technique T1059.001 for command and scripting interpreter further emphasizes the need for comprehensive input validation and execution control measures.