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-2021-33721	SINEC NMS 操作系统命令注入漏洞 — SINEC NMS	7.2	-	2021-08-10
CVE-2021-21805	Advantech R-SeeNet 操作系统命令注入漏洞 — Advantech	9.8	-	2021-08-05
CVE-2021-1602	Cisco Small Business RV160 and RV260 Series VPN Routers Remote Command Execution Vulnerability — Cisco Small Business RV Series Router Firmware	8.2	High	2021-08-04
CVE-2021-32772	Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in helper_entries — poddycast	8.8	High	2021-08-03
CVE-2021-3198	Ivanti MobileIron Core clish Restricted Shell Escape via OS Command Injection — MobileIron Core	6.5	Medium	2021-07-22
CVE-2021-31580	Akkadian Provisioning Manager Engine (PME) Shell Escape via 'exec' command — Provisioning Manager Engine (PME)	8.7	High	2021-07-22
CVE-2021-32751	Arbitrary code execution via specially crafted environment variables — gradle	7.5	High	2021-07-20
CVE-2020-5322	DELL EMC OpenManage Enterprise-Modular 操作系统操作系统命令注入漏洞 — Dell OpenManage Enterprise Modular	9.1	Critical	2021-07-19
CVE-2020-29499	Dell EMC PowerStore 操作系统命令注入漏洞 — PowerStore	6.4	Medium	2021-07-19
CVE-2021-21819	D-LINK DIR-3040 操作系统命令注入漏洞 — D-Link	9.8	-	2021-07-16
CVE-2021-32749	Possible RCE vulnerability in mailing action using mailutils (mail-whois) — fail2ban	6.1	Medium	2021-07-16
CVE-2021-32534	QSAN SANOS - Command Injection — SANOS	9.8	Critical	2021-07-07
CVE-2021-32533	QSAN SANOS - Command Injection — SANOS	9.8	Critical	2021-07-07
CVE-2021-32531	QSAN XEVO - Command Injection Following via Init function — XEVO	9.8	Critical	2021-07-07
CVE-2021-32530	QSAN XEVO - Command Injection Following via Array function — XEVO	9.8	Critical	2021-07-07
CVE-2021-32524	QSAN Storage Manager - Command Injection-3 — Storage Manager	9.1	Critical	2021-07-07
CVE-2021-32513	QSAN Storage Manager - Command Injection Following via QsanTorture function — Storage Manager	9.8	Critical	2021-07-07
CVE-2021-32512	QSAN Storage Manager - Command Injection Following via QuickInstall function — Storage Manager	9.8	Critical	2021-07-07
CVE-2021-28804	Command Injection Vulnerabilities in QTS and QuTS hero — QTS	9.8	-	2021-07-01
CVE-2021-28802	Command Injection Vulnerabilities in QTS and QuTS hero — QTS	9.8	-	2021-07-01
CVE-2021-31838	Command injection through environment variable in MVISION EDR — MVISION EDR	8.4	High	2021-06-29
CVE-2021-33534	WEIDMUELLER: WLAN devices affected by OS Command Injection vulnerability — IE-WL(T)-BL-AP-CL-XX	7.2	High	2021-06-25
CVE-2021-33533	WEIDMUELLER: WLAN devices affected by OS Command Injection vulnerability — IE-WL(T)-BL-AP-CL-XX	8.8	High	2021-06-25
CVE-2021-33532	WEIDMUELLER: WLAN devices affected by OS Command Injection vulnerability — IE-WL(T)-BL-AP-CL-XX	8.8	High	2021-06-25
CVE-2021-33530	WEIDMUELLER: WLAN devices affected by OS Command Injection vulnerability — IE-WL(T)-BL-AP-CL-XX	8.8	High	2021-06-25
CVE-2021-35047	Privileged Command Injection Vulnerability in Fidelis Network and Deception — Fidelis Network	9.9	Critical	2021-06-25
CVE-2021-28800	Command Injection Vulnerability in QTS — QTS	8.1	High	2021-06-24
CVE-2021-32556	apport get_modified_conffiles() function command injection — apport	3.8	Low	2021-06-12
CVE-2021-33841	Circutor SGE-PLC1000 OS command Injection — SGE-PLC1000	10.0	Critical	2021-06-09
CVE-2021-28811	Vulnerability in Roon Server — Roon Server	7.2	High	2021-06-08

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.