CVE-2022-48253 in Nostromo
Summary
by MITRE • 01/11/2023
nhttpd in Nostromo before 2.1 is vulnerable to a path traversal that may allow an attacker to execute arbitrary commands on the remote server. The vulnerability occurs when the homedirs option is used.
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Analysis
by VulDB Data Team • 02/01/2023
The vulnerability identified as CVE-2022-48253 affects nhttpd version 2.0 and earlier in the Nostromo web server software, representing a critical path traversal flaw that can lead to arbitrary code execution on affected systems. This vulnerability specifically manifests when the homedirs option is enabled, which allows the web server to serve content from user home directories. The flaw stems from insufficient input validation and path normalization within the server's handling of HTTP requests, creating an opportunity for attackers to manipulate file paths and access restricted system resources. The issue falls under the category of CWE-22 Path Traversal, which is a well-documented weakness in software systems where user-supplied input is not properly validated before being used to access files or directories.
The technical exploitation of this vulnerability occurs through carefully crafted HTTP requests that leverage the homedirs configuration to traverse directory structures beyond the intended boundaries. When the server processes these malformed requests, it fails to properly sanitize the input paths, allowing attackers to append directory traversal sequences such as "../" or similar constructs. This enables unauthorized access to files outside the designated web root directories, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it operates at the filesystem level, allowing attackers to read sensitive files, execute arbitrary commands, and potentially gain shell access to the underlying operating system. The attack vector aligns with ATT&CK technique T1059 Command and Scripting Interpreter, where adversaries use system commands to execute malicious code.
The operational impact of CVE-2022-48253 extends beyond simple data theft, as successful exploitation can result in full system compromise and persistent access for attackers. Organizations running affected versions of Nostromo web server are at risk of unauthorized access to sensitive data, system files, and configuration information stored within user home directories. The vulnerability affects systems where the homedirs option has been enabled as a legitimate feature for serving user-specific content, making it particularly concerning for environments that rely on this functionality. Attackers can leverage this flaw to escalate privileges, install backdoors, or use the compromised system as a launch point for further attacks within the network infrastructure. The implications are significant for any organization that has not yet updated to version 2.1 or later, as the vulnerability provides a direct path to system control without requiring additional authentication or complex attack chains.
Mitigation strategies for CVE-2022-48253 primarily focus on immediate software updates to version 2.1 or later, which includes the necessary patches to address the path traversal vulnerability. Organizations should also implement network segmentation and access controls to limit exposure of affected systems, particularly those with the homedirs option enabled. Security administrators should conduct thorough audits of all web server configurations to identify and disable unnecessary features that could expose the system to similar vulnerabilities. Additional protective measures include implementing web application firewalls to detect and block suspicious path traversal attempts, monitoring system logs for unusual file access patterns, and establishing robust patch management processes to ensure timely updates of all software components. The remediation process should also involve validating that the updated software properly handles all input validation scenarios and that the homedirs functionality operates within secure boundaries to prevent future exploitation attempts.