Weakness (CWE)
CWE-20: Improper Input Validation
The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.
How to prevent it (8 mitigations)
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Architecture and Design
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses. [REF-1109] [REF-1110] [REF-1111]
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Architecture and Design
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
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Architecture and Design, Implementation
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
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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.
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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.
Even though client-side checks provide minimal benefits with respect to server-side security, they are still useful. First, they can support intrusion detection. If the server receives input that should have been rejected by the client, then it may be an indication of an attack. Second, client-side error-checking can provide helpful feedback to the user about the expectations for valid input. Third, there may be a reduction in server-side processing time for accidental input errors, although this is typically a small savings.
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Implementation
When your application combines data from multiple sources, perform the validation after the sources have been combined. The individual data elements may pass the validation step but violate the intended restrictions after they have been combined.
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Implementation
Be especially careful to validate all input when invoking code that crosses language boundaries, such as from an interpreted language to native code. This could create an unexpected interaction between the language boundaries. Ensure that you are not violating any of the expectations of the language with which you are interfacing. For example, even though Java may not be susceptible to buffer overflows, providing a large argument in a call to native code might trigger an overflow.
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Implementation
Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
Source: MITRE CWE-20
6,593 results · Feed
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Medium 5.3
Goobi viewer: Solr query injection via the legacy RSS servlet q and filterQuery parameters
The Goobi viewer is a web application that allows digitised material to be displayed in a web browser. Prior to version 26.05, the legacy RSS servlet (RssResolver, GET /rss/) accepts the q and filterQuery parameters and concatenates them into Solr queries wit…
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Medium 5.3
Goobi viewer: cleanUpQuery double-brace bypass allows arbitrary Solr local-param injection
The Goobi viewer is a web application that allows digitised material to be displayed in a web browser. From version 23.03 to before version 26.05, SolrTools.cleanUpQuery() strips Solr local-parameter syntax ({!...}) from user-supplied query strings before the…
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Medium 5.3
baserCMS: Mail-form auto-replies accept multiple visitor-controlled recipients
baserCMS is a website development framework. In versions 5.2.5 before 5.3.2 and 5.4.0 before 5.4.2, an unauthenticated visitor can supply a comma-separated address list in a public mail form's email field and cause a single auto-reply to be addressed to multi…
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High 7.0
Heimdall: IP Spoofing via Unvalidated Forwarding Headers
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.17, when the trusted_proxies option is configured, heimdall extracts client IP addresses from the Forwarded (for= parameter) and X-Forwarded-For headers…
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High 7.0
Heimdall: Forwarded Header Injection via Unsanitized Host Header in Proxy Mode
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.17, when Heimdall operates in proxy mode, it constructs the Forwarded HTTP header after executing the matched rule pipeline by inserting the incoming re…
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Medium 6.3
JwtVerifierImpl.Verify does not enforce the JWS `crit` header (RFC 7515 §4.1.11)
gose parsed the JWS `crit` header into `JwsHeader.Crit` and then never read it. RFC 7515 §4.1.11 requires a recipient to reject a JWS whose listed critical extension parameters it does not understand. gose implements no header extensions, so every token carry…
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Medium 4.6
Part-DB: Spreadsheet Formula Injection in XLSX Part Exports
Part-DB is an open source inventory management system for electronic components. Prior to version 2.13.2, Part-DB contains a spreadsheet formula injection vulnerability in the part import/export workflow. An authenticated user with permission to import parts …
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Critical 9.1
Command Execution via Admin Console Input in Okta Access Gateway
An input validation issue in the Okta Access Gateway (OAG) Admin Console allows the processing of specially formatted configuration values. An authenticated administrator can leverage this to execute system commands within the context of the OAG service accou…
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Critical 9.9
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 Stack Buffer Overflow
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped co…
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Medium 4.6
subhajitkhan online-clinic-management-system Appointment Booking patappointtime.php input validation
A flaw has been found in subhajitkhan online-clinic-management-system up to e9ee77a8827a1446220fa07ee693dc4d9a29a578. Impacted is an unknown function of the file patappointtime.php of the component Appointment Booking. This manipulation of the argument day/ti…
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High 7.5
Cisco IOS XR Software for ASR 9000 Series Routers IPv4 Unicast Packets Denial of Service Vulnerability
A vulnerability in the IPv4 packet processing functionality of Cisco IOS XR Software that affects Cisco ASR 9000 and 9900 Series Aggregation Services Routers as well as Cisco ASR 9902 and 9903 Compact High-Performance Routers could allow an unauthenticated, r…
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High 8.8
Cisco Unified Communications Products Hardening Release: October 2026 - Improper Input Validation Vulnerabilities
As part of Cisco's ongoing commitment to proactive security and product quality, engineering teams for Cisco Emergency Responder, Cisco Prime Collaboration Deployment, Cisco Unified Communications Manager (Unified CM), Cisco Unified Communications Manager IM …
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Medium 5.5
Cisco Secure Client Privilege Escalation Vulnerability
A vulnerability in the interprocess communication (IPC) channel of the Secure Firewall Posture module in Cisco Secure Client could allow an authenticated, local attacker to elevate privileges on an affected device. This vulnerability is due to insufficient va…
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Low 2.3
pypdf: Unvalidated JPEG image data loading
pypdf is a free and open-source pure-python PDF library. Prior to 6.21.1, an attacker can craft a PDF containing image data labeled with the /DCTDecode filter that causes Pillow to select and invoke an unintended image parser when the image is loaded. Environ…
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Medium 4.0
Sensitive Data Exposure via URL Parameters in Multiple WSO2 Products Allows Confidential Information Leakage
The product failed to enforce validation constraints on user-supplied input in URL parameters, allowing sensitive data to be passed to flows where it was not intended to be processed. Although the product did not utilize this data, its acceptance could lead t…
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High 8.7
JITServer: Multiple Denial of Service vulnerabilities via out-of-bounds heap reads during message and reply parsing
In Eclipse OpenJ9 versions up to 0.63.0, the JITServer component is vulnerable to denial of service due to improper boundary checks during protocol message and reply handling. An unauthenticated remote attacker or malicious JITServer can transmit malformed ne…
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Medium 4.0CVE-2026-114101 Public exploit
Coraza before 3.8.1 Multipart filename* Charset Handling FILES Rule Bypass
Coraza before 3.8.1 extracts multipart upload filenames with Go's mime.ParseMediaType, which silently ignores RFC 5987 filename* parameters whose charset is not utf-8 or us-ascii. Unauthenticated attackers can send a decoy filename with filename*=iso-8859-1''…
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Medium 5.8
Coraza from 3.0.4 before 3.8.1 Request Body Inspection Bypass via Content-Type
Coraza from 3.0.4 before 3.8.1 contains a request body inspection bypass because request-body processor selection compares the entire Content-Type value exactly, so URL-encoded bodies whose Content-Type carries a media-type parameter are never parsed. Unauthe…
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Medium 5.8
Coraza 3.0.0 before 3.8.1 WAF Bypass via JSON Key Collision
Coraza from 3.0.0 before 3.8.1 has a JSON body processor that flattens nested properties into dot-separated ARGS_POST names without escaping literal dots, so distinct properties collide. Unauthenticated attackers can add a later dotted property such as accoun…
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Medium 4.8
Vyper before 0.2.9 Incorrect RETURNDATASIZE in create_forwarder_to Proxies
Vyper before 0.2.9 deploys forwarder proxies through the built-in create_forwarder_to function that report a fixed 4096-byte RETURNDATASIZE rather than the actual return data size. Calls through these proxies can yield corrupted data when a function returns m…
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Low 3.7
Vyper before 0.3.1 Improper Input Validation of uint8 Interface Return Values
Vyper before 0.3.1 lacks a uint8 type, allowing interface return values declared as uint8, such as ERC20.decimals(), to be stored in uint256 variables without bounds checking. Malicious contracts can return values greater than 255 to manipulate or bypass cont…
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High 7.8
Vulnerability in the Oracle Outside In Technology product of Oracle Fusion Middleware (component: Outside In Core). The…
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High 7.8
Vulnerability in the Oracle Outside In Technology product of Oracle Fusion Middleware (component: Outside In Image Expo…
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High 7.0
Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java S…
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Medium 6.5
Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java S…
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High 7.5
Vulnerability in the Oracle Outside In Technology product of Oracle Fusion Middleware (component: Outside In PDF Export…
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High 7.5
Vulnerability in the Oracle Outside In Technology product of Oracle Fusion Middleware (component: Outside In PDF Export…
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High 8.2
Vulnerability in the Oracle Outside In Technology product of Oracle Fusion Middleware (component: Outside In Clean Cont…
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High 8.8
Improper input validation in Chromoting in Google Chrome prior to 156.0.8078.47 allowed a remote attacker leveraging so…
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High 8.8
Improper input validation in Network in Google Chrome prior to 156.0.8078.47 allowed a remote attacker leveraging socia…
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High 8.8
Improper input validation in PDF in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to potentially bypas…
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High 8.8
Improper input validation in Compositing in Google Chrome prior to 156.0.8078.47 allowed a remote attacker who had comp…
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High 8.8
Improper input validation in Media in Google Chrome prior to 156.0.8078.47 allowed a remote attacker to potentially exe…
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High 8.8
Improper input validation in DataTransfer in Google Chrome prior to 156.0.8078.47 allowed a remote attacker leveraging …
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Medium 6.5
Improper input validation in Core in Google Chrome on on Windows prior to 156.0.8078.47 allowed a remote attacker who h…
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High 8.8
Improper input validation in Omnibox in Google Chrome on on Android prior to 156.0.8078.47 allowed a local attacker lev…
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High 8.8
Improper input validation in Downloads in Google Chrome prior to 156.0.8078.47 allowed a remote attacker who had compro…
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Critical 9.6
Improper input validation in WebAppInstalls in Google Chrome prior to 156.0.8078.47 allowed a remote attacker leveragin…
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Critical 9.6
Improper input validation in Core in Google Chrome prior to 156.0.8078.47 allowed a remote attacker who had compromised…
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High 8.8
Improper input validation in Core in Google Chrome prior to 156.0.8078.47 allowed a remote attacker who had compromised…