CWE-73 (文件名或路径的外部可控制) — Vulnerability Class 437

437 vulnerabilities classified as CWE-73 (文件名或路径的外部可控制). AI Chinese analysis included.

CWE-73 represents a critical input validation weakness where applications allow external actors to dictate file system paths, potentially leading to unauthorized access or modification of sensitive data. Attackers typically exploit this vulnerability through path traversal techniques, injecting sequences like “../” to escape intended directories and reach critical system files or application configurations. This manipulation occurs when software fails to sanitize user-supplied input before using it in filesystem operations, allowing the attacker to bypass intended access controls. To mitigate this risk, developers must implement rigorous input validation, ensuring that all file paths are strictly checked against a whitelist of allowed directories. Additionally, using canonicalization functions to resolve paths before comparison and employing chroot jails can effectively isolate file access, thereby preventing attackers from navigating outside the designated application sandbox.

MITRE CWE Description

The product allows user input to control or influence paths or file names that are used in filesystem operations. This could allow an attacker to access or modify system files or other files that are critical to the application. Path manipulation errors occur when the following two conditions are met: 1. An attacker can specify a path used in an operation on the filesystem. 2. By specifying the resource, the attacker gains a capability that would not otherwise be permitted. For example, the program may give the attacker the ability to overwrite the specified file or run with a configuration controlled by the attacker.

Common Consequences (3)

Integrity, Confidentiality Read Files or Directories, Modify Files or Directories

The application can operate on unexpected files. Confidentiality is violated when the targeted filename is not directly readable by the attacker.

Integrity, Confidentiality, Availability Modify Files or Directories, Execute Unauthorized Code or Commands

The application can operate on unexpected files. This may violate integrity if the filename is written to, or if the filename is for a program or other form of executable code.

Availability DoS: Crash, Exit, or Restart, DoS: Resource Consumption (Other)

The application can operate on unexpected files. Availability can be violated if the attacker specifies an unexpected file that the application modifies. Availability can also be affected if the attacker specifies a filename for a large file, or points to a special device or a file that does not hav…

Mitigations (5)

Architecture and Design When the set of filenames is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames, and reject all other inputs. For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap provide this capability.

Architecture and Design, Operation Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict all access to files within a particular directory. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the oper…

Architecture and Design For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

Implementation Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range…

Effectiveness: High

Implementation Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59).

Examples (2)

The following code uses input from an HTTP request to create a file name. The programmer has not considered the possibility that an attacker could provide a file name such as "../../tomcat/conf/server.xml", which causes the application to delete one of its own configuration files (CWE-22).

String rName = request.getParameter("reportName"); File rFile = new File("/usr/local/apfr/reports/" + rName); ... rFile.delete();

Bad · Java

The following code uses input from a configuration file to determine which file to open and echo back to the user. If the program runs with privileges and malicious users can change the configuration file, they can use the program to read any file on the system that ends with the extension .txt.

fis = new FileInputStream(cfg.getProperty("sub")+".txt"); amt = fis.read(arr); out.println(arr);

Bad · Java

CVE ID	Title	CVSS	Severity	Published
CVE-2023-6618	SourceCodester Simple Student Attendance System index.php file inclusion — Simple Student Attendance System	5.5	Medium	2023-12-08
CVE-2023-5247	Mitsubishi Electric FA Engineering Software 安全漏洞 — GX Works3	7.8	High	2023-11-30
CVE-2023-39542	Foxit Reader 安全漏洞 — Foxit Reader	8.8	High	2023-11-27
CVE-2023-40194	Foxit Reader 安全漏洞 — Foxit Reader	8.8	High	2023-11-27
CVE-2023-35985	Foxit Reader 安全漏洞 — Foxit Reader	8.8	High	2023-11-27
CVE-2023-34982	AVEVA Operations Control Logger External Control of File Name or Path — SystemPlatform	5.5	Medium	2023-11-15
CVE-2023-20114	Cisco Firepower Management Center 安全漏洞 — Cisco Firepower Management Center	6.5	Medium	2023-11-01
CVE-2023-43074	Dell Unity 安全漏洞 — Unity	5.2	Medium	2023-10-23
CVE-2023-36634	Fortinet FortiAP-U 安全漏洞 — FortiAP-U	6.5	High	2023-09-13
CVE-2023-36764	Microsoft SharePoint Server Elevation of Privilege Vulnerability — Microsoft SharePoint Enterprise Server 2016	8.8	High	2023-09-12
CVE-2023-4634	Media Library Assistant <= 3.09 - Unauthenticated Local/Remote File Inclusion & Remote Code Execution — Media Library Assistant	9.8	Critical	2023-09-06
CVE-2023-32615	Open Automation Software OAS Platform 安全漏洞 — OAS Platform	6.5	Medium	2023-09-05
CVE-2023-4749	SourceCodester Inventory Management System index.php file inclusion — Inventory Management System	6.3	Medium	2023-09-04
CVE-2023-20234	Cisco FXOS Software 安全漏洞 — Cisco Adaptive Security Appliance (ASA) Software	4.4	Medium	2023-08-23
CVE-2023-35384	Windows HTML Platforms Security Feature Bypass Vulnerability — Windows 10 Version 1507	5.4	Medium	2023-08-08
CVE-2023-4191	SourceCodester Resort Reservation System index.php file inclusion — Resort Reservation System	6.3	Medium	2023-08-06
CVE-2023-3643	Boss Mini document file inclusion — Boss Mini	7.3	High	2023-07-12
CVE-2023-35308	Windows MSHTML Platform Security Feature Bypass Vulnerability — Windows 10 Version 1809	6.5	Medium	2023-07-11
CVE-2023-3256	Advantech R-SeeNet External Control of File Name or Path — R-SeeNet	8.8	High	2023-06-22
CVE-2023-28603	Zoom VDI client installer 安全漏洞 — Zoom VDI Windows Meeting Client	7.7	High	2023-06-13
CVE-2023-0008	PAN-OS: Local File Disclosure Vulnerability in the PAN-OS Web Interface — PAN-OS	4.4	Medium	2023-05-10
CVE-2023-29324	Windows MSHTML Platform Security Feature Bypass Vulnerability — Windows 10 Version 1809	6.5	Medium	2023-05-09
CVE-2023-2554	External Control of File Name or Path in unilogies/bumsys — unilogies/bumsys	7.1	-	2023-05-05
CVE-2023-30943	Moodle: tinymce loaders susceptible to arbitrary folder creation	6.5	Medium	2023-05-02
CVE-2023-2152	SourceCodester Student Study Center Desk Management System index.php file inclusion — Student Study Center Desk Management System	5.3	Medium	2023-04-18
CVE-2021-4332	The Plus Addons for Elementor PRO <= 4.1.9 & The Plus Addons for Elementor <= 2.0.6 - Authenticated (Contributor+) Arbitrary File Read — The Plus Addons for Elementor – Addons for Elementor, Page Templates, Widgets, Mega Menu, WooCommerce	6.5	Medium	2023-03-07
CVE-2023-1105	External Control of File Name or Path in flatpressblog/flatpress — flatpressblog/flatpress	8.1	-	2023-03-01
CVE-2023-1070	External Control of File Name or Path in nilsteampassnet/teampass — nilsteampassnet/teampass	9.4	-	2023-02-27
CVE-2022-39952	Fortinet FortiNAC 安全漏洞 — FortiNAC	9.8	Critical	2023-02-16
CVE-2023-21566	Visual Studio Elevation of Privilege Vulnerability — Microsoft Visual Studio 2017 version 15.9 (includes 15.0 - 15.8)	7.8	High	2023-02-14

Vulnerabilities classified as CWE-73 (文件名或路径的外部可控制) represent 437 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.