CWE-78 (OS命令中使用的特殊元素转义处理不恰当(OS命令注入)) — Vulnerability Class 4008

4008 vulnerabilities classified as CWE-78 (OS命令中使用的特殊元素转义处理不恰当(OS命令注入)). AI Chinese analysis included.

CWE-78 represents a critical input validation weakness where software constructs operating system commands using untrusted external data without proper sanitization. Attackers typically exploit this by injecting malicious shell metacharacters, such as semicolons or pipes, into user-supplied fields like form inputs or URL parameters. This manipulation allows the attacker to alter the intended command structure, enabling arbitrary code execution, data exfiltration, or complete system compromise. To mitigate this risk, developers must strictly avoid passing user input directly to OS command interpreters. Instead, they should utilize safe, language-specific APIs that do not invoke the shell, or implement rigorous input validation and parameterization techniques. By treating all external data as inherently untrusted and applying strict allow-list filtering, organizations can effectively neutralize special elements and prevent command injection vulnerabilities.

MITRE CWE Description

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. This weakness can lead to a vulnerability in environments in which the attacker does not have direct access to the operating system, such as in web applications. Alternately, if the weakness occurs in a privileged program, it could allow the attacker to specify commands that normally would not be accessible, or to call alternate commands with privileges that the attacker does not have. The problem is exacerbated if the compromised process does not follow the principle of least privilege, because the attacker-controlled commands may run with special system privileges that increases the amount of damage. There are at least two subtypes of OS command injection: The application intends to execute a single, fixed program that is under its own control. It intends to use externally-supplied inputs as arguments to that program. For example, the program might use system("nslookup [HOSTNAME]") to run nslookup and allow the user to supply a HOSTNAME, which is used as an argument. Attackers cannot prevent nslookup from executing. However, if the program does not remove command separators from the HOSTNAME argument, attackers could place the separators into the arguments, which allows them to execute their own program afte…

Common Consequences (1)

Confidentiality, Integrity, Availability, Non-Repudiation Execute Unauthorized Code or Commands, DoS: Crash, Exit, or Restart, Read Files or Directories, Modify Files or Directories, Read Application Data, Modify Application Data, Hide Activities

Attackers could execute unauthorized operating system commands, which could then be used to disable the product, or read and modify data for which the attacker does not have permissions to access directly. Since the targeted application is directly executing the commands instead of the attacker, any…

Mitigations (5)

Architecture and Design If at all possible, use library calls rather than external processes to recreate the desired functionality.

Architecture and Design, Operation Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software. OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For ex…

Effectiveness: Limited

Architecture and Design For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.

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.

Architecture and Design Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.

Examples (2)

This example code intends to take the name of a user and list the contents of that user's home directory. It is subject to the first variant of OS command injection.

$userName = $_POST["user"]; $command = 'ls -l /home/' . $userName; system($command);

Bad · PHP

;rm -rf /

Attack

The following simple program accepts a filename as a command line argument and displays the contents of the file back to the user. The program is installed setuid root because it is intended for use as a learning tool to allow system administrators in-training to inspect privileged system files without giving them the ability to modify them or damage the system.

int main(int argc, char** argv) { char cmd[CMD_MAX] = "/usr/bin/cat "; strcat(cmd, argv[1]); system(cmd); }

Bad · C

CVE ID	Title	CVSS	Severity	Published
CVE-2020-26301	Command injection in mscdex/ssh2 — ssh2	7.5	High	2021-09-20
CVE-2021-37913	HGiga OAKlouds - Command Injection-2 — OAKlouds OAKSv2	9.8	Critical	2021-09-15
CVE-2021-37912	HGiga OAKlouds - Command Injection-1 — OAKlouds OAKSv2	9.8	Critical	2021-09-15
CVE-2021-23025	F5 BIG-IP 操作系统命令注入漏洞 — BIG-IP	8.8	-	2021-09-14
CVE-2021-23031	F5 BIG-IP 操作系统命令注入漏洞 — BIG-IP Advanced WAF and BIG-IP ASM	8.8	-	2021-09-14
CVE-2021-31891	Siemens Desigo CC 操作系统命令注入漏洞 — Desigo CC	10.0	-	2021-09-14
CVE-2021-33554	UDP Technology/Geutebrück camera devices: Command injection in appfile.filename parameter leading to RCE — E2 Series	7.2	High	2021-09-13
CVE-2021-33553	UDP Technology/Geutebrück camera devices: Command injection in command parameter leading to RCE — E2 Series	7.2	High	2021-09-13
CVE-2021-33552	UDP Technology/Geutebrück camera devices: Command injection in date parameter leading to RCE — E2 Series	7.2	High	2021-09-13
CVE-2021-33551	UDP Technology/Geutebrück camera devices: Command injection in environment.lang parameter leading to RCE — E2 Series	7.2	High	2021-09-13
CVE-2021-33550	UDP Technology/Geutebrück camera devices: Command injection in date parameter leading to RCE — E2 Series	7.2	High	2021-09-13
CVE-2021-33548	UDP Technology/Geutebrück camera devices: Command injection in preserve parameter leading to RCE — E2 Series	7.2	High	2021-09-13
CVE-2021-33544	UDP Technology/Geutebrück camera devices: command injection leading to RCE — E2 Series	7.2	High	2021-09-13
CVE-2021-34728	Cisco IOS XR Software Authenticated User Privilege Escalation Vulnerabilities — Cisco IOS XR Software	7.8	High	2021-09-09
CVE-2021-34722	Cisco IOS XR Software Command Injection Vulnerabilities — Cisco IOS XR Software	6.7	Medium	2021-09-09
CVE-2021-34721	Cisco IOS XR Software Command Injection Vulnerabilities — Cisco IOS XR Software	6.7	Medium	2021-09-09
CVE-2021-34719	Cisco IOS XR Software Authenticated User Privilege Escalation Vulnerabilities — Cisco IOS XR Software	7.8	High	2021-09-09
CVE-2021-28571	Adobe After Effects improper neutralization of special elements could lead to remote code execution — After Effects	8.3	High	2021-09-08
CVE-2021-36024	Magento Commerce Improper Neutralization of Special Elements Used In A Command — Magento Commerce	9.1	Critical	2021-09-01
CVE-2021-36022	Magento Commerce Widgets Update Layout XML Injection Vulnerability Could Lead To Remote Code Execution — Magento Commerce	9.1	Critical	2021-09-01
CVE-2021-1584	Cisco Nexus 9000 Series Fabric Switches ACI Mode Privilege Escalation Vulnerability — Cisco NX-OS System Software in ACI Mode	6.0	Medium	2021-08-25
CVE-2021-33191	MiNiFi CPP arbitrary script execution is possible on the agent's host machine through the c2 protocol — Apache NiFi - MiNiFi C++	9.8	-	2021-08-24
CVE-2021-36011	Adobe Illustrator improper neutralization of special elements used in an OS command — Illustrator	8.3	High	2021-08-20
CVE-2021-28634	Adobe Acrobat Reader AcrobatUtils.scpt Extension OS Command Injection Vulnerability — Acrobat Reader	8.2	High	2021-08-20
CVE-2021-32830	Github diez 命令注入漏洞 — diez	3.9	Low	2021-08-17
CVE-2021-3617	Lenovo Smart Camera 命令注入漏洞 — Smart Camera X3, X5, and C2E firmware	7.2	High	2021-08-17
CVE-2021-3459	Motorola MM1000 操作系统命令注入漏洞 — MM1000 MoCA Adapter	6.8	Medium	2021-08-17
CVE-2021-32826	Remote code execution in Proxyee-Down — proxyee-down	6.8	Medium	2021-08-16
CVE-2021-3708	D-Link DSL-2750U 操作系统命令注入漏洞 — DSL-2750U	7.8	-	2021-08-16
CVE-2021-3050	PAN-OS: OS Command Injection Vulnerability in Web Interface — PAN-OS	8.8	High	2021-08-11

Vulnerabilities classified as CWE-78 (OS命令中使用的特殊元素转义处理不恰当(OS命令注入)) represent 4008 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.