Weakness (CWE)
CWE-94: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How to prevent it (7 mitigations)
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Architecture and Design
Refactor your program so that you do not have to dynamically generate code.
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Architecture and Design
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 which code can be executed by your product.
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 operating system; the rest of your application may still be subject to compromise.
Be careful to avoid CWE-243 and other weaknesses related to jails.
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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 of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
To reduce the likelihood of code injection, use stringent allowlists that limit which constructs are allowed. If you are dynamically constructing code that invokes a function, then verifying that the input is alphanumeric might be insufficient. An attacker might still be able to reference a dangerous function that you did not intend to allow, such as system(), exec(), or exit().
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Testing
Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
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Operation
Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
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Operation
Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
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Implementation
For Python programs, it is frequently encouraged to use the ast.literal_eval() function instead of eval, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].
Source: MITRE CWE-94
78 results · Clear filters · Feed
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Critical 9.8
Spring Cloud Function Code Injection with a specially crafted SpEL as a routing expression
In Spring Cloud Function versions 3.1.6, 3.2.2 and older unsupported versions, when using routing functionality it is possible for a user to provide a specially crafted SpEL as a routing-expression that may result in remote code execution and access to local …
KEV Aug 25, 2022 -
Critical 10.0
Spring Cloud Gateway vulnerable to Code Injection when Gateway Actuator endpoint enabled, exposed, unsecured
In spring cloud gateway versions prior to 3.1.1+ and 3.0.7+ , applications are vulnerable to a code injection attack when the Gateway Actuator endpoint is enabled, exposed and unsecured. A remote attacker could make a maliciously crafted request that could al…
KEV May 16, 2022 -
Critical 9.8
A code injection vulnerability in the Ivanti EPM Cloud Services Appliance (CSA) allows an unauthenticated user to execu…
KEV Mar 25, 2024 -
High 8.5
XStream is vulnerable to a Remote Command Execution attack
XStream is a simple library to serialize objects to XML and back again. In affected versions this vulnerability may allow a remote attacker has sufficient rights to execute commands of the host only by manipulating the processed input stream. No user is affec…
KEV Mar 10, 2023 -
High 7.2
A vulnerability allowed multiple unrestricted uploads in Pulse Connect Secure before 9.1R11.4 that could lead to an aut…
KEV Nov 3, 2021 -
High 8.8
A buffer overflow vulnerability exists in Pulse Connect Secure before 9.1R11.4 allows a remote authenticated attacker t…
KEV Nov 3, 2021 -
Critical 10.0
An issue has been discovered in GitLab CE/EE affecting all versions starting from 11.9. GitLab was not properly validat…
KEV Nov 3, 2021 -
Medium 6.8
Improper neutralization of user data in the DjVu file format in ExifTool versions 7.44 and up allows arbitrary code exe…
KEV Nov 17, 2021 -
Critical 9.8
Unauthenticated remote code execution in Ignition
Ignition before 2.5.2, as used in Laravel and other products, allows unauthenticated remote attackers to execute arbitrary code because of insecure usage of file_get_contents() and file_put_contents(). This is exploitable on sites using debug mode with Larave…
KEV Sep 18, 2023 -
Critical 9.8
Remote code execution in Apache Struts
Forced OGNL evaluation, when evaluated on raw user input in tag attributes, may lead to remote code execution. Affected software : Apache Struts 2.0.0 - Struts 2.5.25.
KEV Nov 3, 2021 -
High 7.2
A vulnerability in the Pulse Connect Secure < 9.1R8.2 admin web interface could allow an authenticated attacker to uplo…
KEV Nov 3, 2021 -
High 7.2
A code injection vulnerability exists in Pulse Connect Secure <9.1R8 that allows an attacker to crafted a URI to perfor…
KEV Mar 7, 2022 -
Critical 9.8
PlaySMS before 1.4.3 does not sanitize inputs from a malicious string.
KEV Nov 3, 2021 -
High 7.5
Improper Input Validation in Apache Solr
Apache Solr 5.0.0 to Apache Solr 8.3.1 are vulnerable to a Remote Code Execution through the VelocityResponseWriter. A Velocity template can be provided through Velocity templates in a configset `velocity/` directory or as a parameter. A user defined configse…
KEV Nov 3, 2021 -
Critical 9.9
Remote Code Execution Vulnerability in NPM mongo-express
mongo-express before 0.54.0 is vulnerable to Remote Code Execution via endpoints that uses the `toBSON` method. A misuse of the `vm` dependency to perform `exec` commands in a non-safe environment.
KEV Dec 10, 2021 -
Critical 10.0
IBM Planning Analytics 2.0.0 through 2.0.8 is vulnerable to a configuration overwrite that allows an unauthenticated us…
KEV Nov 3, 2021 -
Critical 9.8
vBulletin 5.x through 5.5.4 allows remote command execution via the widgetConfig[code] parameter in an ajax/render/widg…
KEV Nov 3, 2021 -
High 7.2
XML External Entity (XXE) Injection in Apache Solr
In Apache Solr, the DataImportHandler, an optional but popular module to pull in data from databases and other sources, has a feature in which the whole DIH configuration can come from a request's "dataConfig" parameter. The debug mode of the DIH admin screen…
KEV Dec 10, 2021 -
Critical 9.8
Kibana versions before 5.6.15 and 6.6.1 contain an arbitrary code execution flaw in the Timelion visualizer. An attacke…
KEV Jan 10, 2022 -
Critical 9.8
Richfaces vulnerable to arbitrary code execution
The RichFaces Framework 3.X through 3.3.4 is vulnerable to Expression Language (EL) injection via the UserResource resource. A remote, unauthenticated attacker could exploit this to execute arbitrary code using a chain of java serialized objects via org.ajax4…
KEV Sep 28, 2023 -
High 8.1
Drupal core - Highly critical - Remote Code Execution - SA-CORE-2018-004
A remote code execution vulnerability exists within multiple subsystems of Drupal 7.x and 8.x. This potentially allows attackers to exploit multiple attack vectors on a Drupal site, which could result in the site being compromised. This vulnerability is relat…
KEV Apr 13, 2022 -
Critical 9.8
Spring Data Commons remote code injection vulnerability
Spring Data Commons, versions prior to 1.13 to 1.13.10, 2.0 to 2.0.5, and older unsupported versions, contain a property binder vulnerability caused by improper neutralization of special elements. An unauthenticated remote malicious user (or attacker) can sup…
KEV Mar 25, 2022 -
High 7.8
Microsoft .NET Framework 2.0, 3.5, 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2 and 4.7 allow an attacker to execute code remotely v…
KEV Nov 3, 2021 -
High 8.8
DNN (aka DotNetNuke) has Remote Code Execution via a cookie
DNN (aka DotNetNuke) before 9.1.1 has Remote Code Execution via a cookie, aka "2017-08 (Critical) Possible remote code execution on DNN sites."
KEV Nov 3, 2021 -
Critical 9.8
Code Injection in PHPUnit
Util/PHP/eval-stdin.php in PHPUnit before 4.8.28 and 5.x before 5.6.3 allows remote attackers to execute arbitrary PHP code via HTTP POST data beginning with a "<?php " substring, as demonstrated by an attack on a site with an exposed /vendor folder, i.e., ex…
KEV Feb 15, 2022 -
Critical 9.8
Samba since version 3.5.0 and before 4.6.4, 4.5.10 and 4.4.14 is vulnerable to remote code execution vulnerability, all…
KEV Mar 30, 2023 -
Critical 9.8
HTTP.sys in Microsoft Windows 7 SP1, Windows Server 2008 R2 SP1, Windows 8, Windows 8.1, and Windows Server 2012 Gold a…
KEV Feb 10, 2022 -
High 8.8
win32k.sys in the kernel-mode drivers in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 …
KEV May 25, 2022 -
Critical 9.8
The findMacroMarker function in parserLib.pas in Rejetto HTTP File Server (aks HFS or HttpFileServer) 2.3x before 2.3c …
KEV Mar 25, 2022 -
High 7.8
GDI+ in Microsoft Windows Vista SP2 and Server 2008 SP2; Office 2003 SP3, 2007 SP3, and 2010 SP1 and SP2; Office Compat…
KEV Feb 15, 2022 -
Critical 9.8
HP ProCurve Manager (PCM) 3.20 and 4.0, PCM+ 3.20 and 4.0, Identity Driven Manager (IDM) 4.0, and Application Lifecycle…
KEV Mar 25, 2022 -
High 7.8
Unspecified vulnerability in Adobe Flash Player before 11.3.300.271 on Windows and Mac OS X and before 11.2.202.238 on …
KEV Mar 3, 2022 -
High 8.8
The (1) ListView, (2) ListView2, (3) TreeView, and (4) TreeView2 ActiveX controls in MSCOMCTL.OCX in the Common Control…
KEV Nov 3, 2021 -
Critical 9.8
Apache Struts Remote Java Code Execution
The ExceptionDelegator component in Apache Struts before 2.2.3.1 interprets parameter values as OGNL expressions during certain exception handling for mismatched data types of properties, which allows remote attackers to execute arbitrary Java code via a craf…
KEV Jan 21, 2022 -
High 7.8
Excel in Microsoft Office 2000 SP3, Office XP SP3, Office 2003 SP3, and Office 2004 and 2008 for Mac; Excel in 2007 Mic…
KEV Jun 8, 2022 -
High 8.8
Microsoft Office PowerPoint 2000 SP3, 2002 SP3, and 2003 SP3, and PowerPoint in Microsoft Office 2004 for Mac, allows r…
KEV Jan 7, 2026 -
Critical 9.8
Static code injection vulnerability in setup.php in phpMyAdmin 2.11.x before 2.11.9.5 and 3.x before 3.1.3.1 allows rem…
KEV Mar 25, 2022 -
High 8.8
Microsoft Office Excel 2000 SP3, 2002 SP3, 2003 SP3, and 2007 SP1; Excel Viewer 2003 Gold and SP3; Excel Viewer; Compat…
KEV Apr 14, 2026