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
2,572 results · Clear filters · Feed
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Medium 6.4
Backstage: Improper input validation in proxy-backend
Backstage is an open framework for building developer portals. Prior to 0.6.17, the @backstage/plugin-proxy-backend package is affected by improper input validation in proxy-backend. An authenticated Backstage user could craft a request URL that causes the pr…
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Medium 6.5
Improper input validation in Extensions in Google Chrome prior to 155.0.8059.39 allowed a remote attacker leveraging so…
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Medium 5.4
Improper input validation in WebAudio in Google Chrome prior to 155.0.8059.39 allowed a remote attacker who had comprom…
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Medium 6.5
Improper input validation in Mobile in Google Chrome on on iOS prior to 155.0.8059.39 allowed a remote attacker leverag…
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Medium 6.5
Improper input validation in SignIn in Google Chrome prior to 155.0.8059.39 allowed a remote attacker leveraging social…
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Medium 4.2
Improper input validation in Compositing in Google Chrome prior to 155.0.8059.39 allowed a remote attacker who had comp…
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Medium 5.9
Improper input validation in Mobile in Google Chrome on on iOS prior to 155.0.8059.39 allowed a remote attacker to obta…
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Medium 6.5
Improper input validation in Viz in Google Chrome prior to 155.0.8059.39 allowed a remote attacker who had compromised …
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Medium 5.4
Improper input validation in Omnibox in Google Chrome on on Android prior to 155.0.8059.39 allowed a remote attacker le…
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Medium 5.1
L4L
Improper input validation vulnerability in Johnson Controls Illustra Standard - L4L China on Windows allows OS Command Injection. This issue affects Illustra Standard - L4L China: before 6.0.0.66394.
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Medium 6.5
vLLM: Structured-output request errors escape the request boundary and terminate the shared EngineCore — engine-fatal denial of service (3 sites)
vLLM is an inference and serving engine for large language models. Prior to 0.30.0, structured-output request failures can escape request-scoped validation and reach the EngineCore fatal-error path. A per-request backend mismatch can re-raise a grammar compil…
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Medium 6.5
vLLM: Loose `cache_salt` validation lets a single request kill EngineCore on LMCache-MP deployments — uncaught downstream `ValueError` denial of service
vLLM is an inference and serving engine for large language models. Prior to 0.30.0, OpenAI-compatible request models accept a non-empty cache_salt value without enforcing the character and length restrictions required by the IPCCacheServerKey consumer in LMCa…
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Medium 6.5
vLLM: Scale-out disaggregated multimodal transport trusts caller-supplied features
vLLM is an inference and serving engine for large language models. Prior to 0.30.0, the /inference/v1/generate endpoint in the disaggregated scale-out path accepts caller-supplied tensors in the features.kwargs_data field, cache identifiers in the features.mm…
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Medium 5.5
In setPermissionGrantState of DevicePolicyManagerService.java, there is a possible persistent denial of service due to …
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Medium 6.1
OpenAM before 16.1.3 Email Content Injection via Users REST Self-Service Actions
OpenAM before 16.1.3 contains an email content injection vulnerability that allows unauthenticated attackers to control notification email wording via the forgotPassword and register actions on /json/{realm}/users. Attackers can supply subject and message fie…
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Medium 6.5
Zebra before 8.0.0 Denial of Service via z_listunifiedreceivers RPC
ZcashFoundation Zebra zebra-rpc before 8.0.0 and zebrad before 4.5.0 contain a reachable assertion in the z_listunifiedreceivers RPC handler, which calls expect() on Sapling receiver parsing that fails for Unified Addresses carrying invalid Jubjub points. Aut…
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Medium 4.3
HCL BigFix Service Management is affected by multiple security vulnerabilities.
HCL BigFix Service Management is affected by an Improper Input Validation vulnerability, which could allow an attacker to inject unvalidated, malformed data into the application, enabling potential injection attacks or errors in downstream processing systems.
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Medium 6.7
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the firmware where an attacker could cause …
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Medium 6.7
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the firmware where an attacker could cause …
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Medium 6.7
VIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer where an attacker coul…
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Medium 6.7
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer where an attacker cou…
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Medium 6.7
NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer where an attacker cou…
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Medium 6.2
MISP Stored Cross-Site Scripting via Unvalidated Galaxy Icon Field in Correlation Graph
MISP contains a stored cross-site scripting (XSS) vulnerability in the galaxy icon handling path. The icon field of a galaxy object was persisted without any server-side validation through the galaxy add, edit, and sync/import capture endpoints. The stored va…
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Medium 6.5
Apache MINA SSHD: Remote execution of JGit "archive -o=file.zip" can write file on the server
Improper input validation in sshd-git in Apache MINA SSHD, versions up to 2.19.0 and 3.0.0-M1 to 3.0.0-M5. Apache MINA SSHD is a Java library for client-side and server-side SSH. Component org.apache.sshd:sshd-git provides though class GitPgmCommandFactory a …
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Medium 5.4
Improper input validation in Passwords in Google Chrome prior to 154.0.8037.57 allowed a remote attacker to spoof UI el…
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Medium 6.5
Improper input validation in Auth in Google Chrome prior to 154.0.8037.57 allowed a remote attacker who had compromised…
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Medium 4.7
DOMSanitizer - Incomplete data: URL Sanitization in DOMSanitizer::isDangerousUrl() Allows Base64-Encoded Payloads to Bypass href and xlink:href Validation
DOMSanitizer is a DOM/SVG/MathML Sanitizer for PHP 7.3+. Prior to version 1.0.15, the isDangerousUrl() method is responsible for rejecting dangerous URL values in the href and xlink:href attributes. The weakness is that "javascript:" is rejected as a scheme, …
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Medium 4.3
Insufficient validation of untrusted input in Codecs in Google Chrome prior to 147.0.7727.55 allowed a remote attacker …
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Medium 6.5
Barco ClickShare CX-20 Gen2 Wallpaper Upload wallpaper improper validation of syntactic correctness of input
A vulnerability was determined in Barco ClickShare CX-20 Gen2 up to 02.26.00.0007. Affected by this issue is some unknown functionality of the file /wallpaper of the component Wallpaper Upload. This manipulation of the argument wallpaper causes improper valid…
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Medium 6.3
Vulnerability-Lookup - Race Condition in Account Recovery Token Consumption Allows Password Takeover
The account recovery (password reset) functionality in the vulnerability-lookup web application contains a time-of-check-to-time-of-use (TOCTOU) race condition in the consumption of single-use recovery tokens. The original implementation verified the token no…
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Medium 5.3
Nodemailer before 10.0.9 Malformed Envelope Recipient via RFC 5322 Comment
Nodemailer is a Node.js email-sending library. In versions >= 9.1.0 and < 10.0.9, the address parser (src/addressparser) mishandles addresses whose local-part is a quoted string and that are followed by RFC 5322 comments, allowing trailing comment-separated d…
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Medium 5.9
vLLM 0.22.0 through 0.23.0 Denial of Service via stop_token_ids
vLLM versions 0.22.0 through 0.23.0 fail to validate stop_token_ids against vocabulary bounds in Rust HTTP and gRPC frontends, allowing out-of-vocabulary token IDs to reach MinTokensLogitsProcessor. Attackers can submit requests with min_tokens greater than z…
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Medium 5.3
vLLM before 0.29.0 CPU Exhaustion via unbounded cache_salt
vLLM versions before 0.29.0 contain a denial-of-service vulnerability in the cache_salt parameter accepted on OpenAI-compatible and Anthropic API endpoints, which lacks maximum length validation and is processed on the single EngineCore scheduler thread. Unau…
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Medium 5.3
Zammad: Remote image tracking bypass via shortened URL scheme
Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, zammad's HTML sanitizer, which blocks remote images in ticket articles and email views, can be bypassed using a shortened URL format that omits the double slash after the sche…
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Medium 5.3
Zammad: Malicious input in Ticket Body Enables Session Termination
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, vulnerability in Zammad's HTML sanitization allows injection of specific HTML elements into ticket bodies. When another user views the crafted ticket, the injected element can…
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Medium 4.1
langchain4j LangChain4j-agentic AgenticScopeJsonSerializationIT.java AgenticScopeSerializer.fromJson deserialization
A flaw has been found in langchain4j up to 1.5.3-beta10/1.11.10-beta18/1.18.1-beta27. This vulnerability affects the function AgenticScopeSerializer.fromJson of the file AgenticScopeJsonSerializationIT.java of the component LangChain4j-agentic. This manipulat…
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Medium 6.9
AIL Framework Onion Module: Non-Onion URL Accepted as Crawler Task Due to Bypassed Domain Validation
The Onion module in AIL Framework contained a performance shortcut in its URL extraction logic that accepted URLs as valid .onion targets based solely on a length check (exactly 69 characters) and a suffix check (ending in ".onion"), without performing proper…
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Medium 6.3
Ail Framework Crawler: Missing Cookiejar Authorization Check Allows Cross-Organization Cookiejar Attachment
The AIL Framework crawler task creation API (api_add_crawler_task) contained an insufficient authorization check when a user supplied a cookiejar UUID to attach to a one-shot or scheduled crawler task. The original code only verified that the cookiejar existe…
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Medium 5.0
Forced local Unix socket connection via dot-sock KMS endpoint in client-side field encryption
The client-side field level encryption support in the MongoDB Python Driver can treat a key management endpoint value ending in ".sock" as a local Unix domain socket path rather than a remote host. A user with write access to the encryption key metadata store…
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Medium 5.4
Discourse: Block post iframes whose encoded userinfo bypasses the allowed_iframes allowlist
Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the Discourse post sanitizer allowed a stored cross-origin iframe to bypass the allowed_iframes prefix policy when the iframe src contained encoded userinfo.…