move system prompt injection to non-experimental

This commit is contained in:
BazookaMusic
2026-05-20 10:48:07 +02:00
parent 5ef09a102c
commit 6c5c8e1c9b
15 changed files with 111 additions and 13 deletions

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@@ -4,14 +4,13 @@
* @problem.severity error
* @security-severity 5.0
* @precision high
* @id js/prompt-injection
* @id js/system-prompt-injection
* @tags security
* experimental
* external/cwe/cwe-1427
*/
import javascript
import experimental.semmle.javascript.security.PromptInjection.SystemPromptInjectionQuery
import semmle.javascript.security.dataflow.SystemPromptInjectionQuery
import SystemPromptInjectionFlow::PathGraph
from SystemPromptInjectionFlow::PathNode source, SystemPromptInjectionFlow::PathNode sink

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@@ -23,4 +23,4 @@ app.get("/chat", async (req, res) => {
});
res.json(response);
});
});

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@@ -0,0 +1,41 @@
<!DOCTYPE qhelp PUBLIC
"-//Semmle//qhelp//EN"
"qhelp.dtd">
<qhelp>
<overview>
<p>If untrusted input is included in a user-role prompt sent to an AI model, an attacker can inject
instructions that manipulate the model's behavior. This is known as <i>indirect prompt injection</i>
when the malicious content arrives through data the model processes, or <i>direct prompt injection</i>
when the attacker controls the prompt directly.</p>
<p>Unlike system prompt injection, user prompt injection targets the user-role messages. Although
user messages are expected to carry user input, passing unsanitized data directly into structured
prompt templates can still allow an attacker to override intended instructions, extract sensitive
context, or trigger unintended tool calls.</p>
</overview>
<recommendation>
<p>To mitigate user prompt injection:</p>
<ul>
<li>Validate user input against a fixed allowlist of permitted values before including it in a prompt.</li>
<li>Use parameterized prompt templates that clearly separate instructions from user data.</li>
<li>Apply output filtering to detect and block responses that indicate prompt injection attempts.</li>
</ul>
</recommendation>
<example>
<p>In the following example, user-controlled data is inserted directly into a user-role prompt
without any validation, allowing an attacker to inject arbitrary instructions.</p>
<sample src="examples/user-prompt-injection.js" />
<p>The fix validates the user input against a fixed allowlist of permitted values before
including it in the prompt.</p>
<sample src="examples/user-prompt-injection_fixed.js" />
</example>
<references>
<li>OWASP: <a href="https://genai.owasp.org/llmrisk/llm01-prompt-injection/">LLM01: Prompt Injection</a>.</li>
<li>MITRE CWE: <a href="https://cwe.mitre.org/data/definitions/1427.html">CWE-1427: Improper Neutralization of Input Used for LLM Prompting</a>.</li>
</references>
</qhelp>

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@@ -3,9 +3,9 @@
* @description Untrusted input flowing into a user-role prompt of an AI model
* may allow an attacker to manipulate the model's behavior.
* @kind path-problem
* @problem.severity error
* @problem.severity warning
* @security-severity 5.0
* @precision high
* @precision medium
* @id js/user-prompt-injection
* @tags security
* experimental

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@@ -0,0 +1,26 @@
const express = require("express");
const OpenAI = require("openai");
const app = express();
const client = new OpenAI();
app.get("/chat", async (req, res) => {
let topic = req.query.topic;
// BAD: user input is used directly in a user-role prompt
const response = await client.chat.completions.create({
model: "gpt-4.1",
messages: [
{
role: "system",
content: "You are a helpful assistant that summarizes topics.",
},
{
role: "user",
content: "Summarize the following topic: " + topic,
},
],
});
res.json(response);
});

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@@ -0,0 +1,32 @@
const express = require("express");
const OpenAI = require("openai");
const app = express();
const client = new OpenAI();
const ALLOWED_TOPICS = ["science", "history", "technology"];
app.get("/chat", async (req, res) => {
let topic = req.query.topic;
// GOOD: user input is validated against a fixed allowlist before use in a prompt
if (!ALLOWED_TOPICS.includes(topic)) {
return res.status(400).json({ error: "Invalid topic" });
}
const response = await client.chat.completions.create({
model: "gpt-4.1",
messages: [
{
role: "system",
content: "You are a helpful assistant that summarizes topics.",
},
{
role: "user",
content: "Summarize the following topic: " + topic,
},
],
});
res.json(response);
});

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@@ -1,55 +0,0 @@
/**
* Provides classes modeling security-relevant aspects of the `@anthropic-ai/sdk` package.
* See https://github.com/anthropics/anthropic-sdk-typescript
*
* Structurally typed sinks (system, beta.agents) have been moved to
* Models as Data: javascript/ql/lib/ext/anthropic.model.yml
*
* This file retains only role-filtered message sinks that require inspecting
* a sibling `role` property, which MaD cannot express.
*/
private import javascript
module Anthropic {
/** Gets a reference to the `Anthropic` client instance. */
private API::Node classRef() {
result = API::moduleImport("@anthropic-ai/sdk").getInstance()
}
/** Gets a reference to the messages.create params (both stable and beta). */
private API::Node messagesCreateParams() {
result = classRef().getMember("messages").getMember("create").getParameter(0)
or
result =
classRef().getMember("beta").getMember("messages").getMember("create").getParameter(0)
}
/**
* Gets role-filtered system/assistant message sinks.
* These require checking a sibling `role` property and cannot be expressed in MaD.
*/
API::Node getSystemOrAssistantPromptNode() {
// messages: [{ role: "assistant", content: "..." }]
exists(API::Node msg |
msg = messagesCreateParams().getMember("messages").getArrayElement() and
msg.getMember("role").asSink().mayHaveStringValue(["system", "assistant"])
|
result = msg.getMember("content")
)
}
/**
* Gets role-filtered user message sinks.
* These require checking a sibling `role` property and cannot be expressed in MaD.
*/
API::Node getUserPromptNode() {
// messages: [{ role: "user", content: "..." }]
exists(API::Node msg |
msg = messagesCreateParams().getMember("messages").getArrayElement() and
not msg.getMember("role").asSink().mayHaveStringValue(["system", "assistant"])
|
result = msg.getMember("content")
)
}
}

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@@ -1,61 +0,0 @@
/**
* Provides classes modeling security-relevant aspects of the `@google/genai` package.
* See https://github.com/googleapis/js-genai
*
* Structurally typed sinks (systemInstruction, prompt, message, etc.) have been
* moved to Models as Data: javascript/ql/lib/ext/google-genai.model.yml
*
* This file retains only role-filtered content sinks that require inspecting
* a sibling `role` property, which MaD cannot express.
*/
private import javascript
module GoogleGenAI {
/** Gets a reference to the `GoogleGenAI` client instance. */
private API::Node clientRef() {
result =
API::moduleImport("@google/genai").getMember("GoogleGenAI").getInstance()
}
/**
* Gets role-filtered system/model message sinks.
* These require checking a sibling `role` property and cannot be expressed in MaD.
*/
API::Node getSystemOrAssistantPromptNode() {
// contents: [{ role: "model", parts: [{ text: "..." }] }]
// Gemini uses "model" role instead of "assistant"
exists(API::Node msg |
msg =
clientRef()
.getMember("models")
.getMember(["generateContent", "generateContentStream"])
.getParameter(0)
.getMember("contents")
.getArrayElement() and
msg.getMember("role").asSink().mayHaveStringValue(["system", "model"])
|
result = msg.getMember("parts").getArrayElement().getMember("text")
)
}
/**
* Gets role-filtered user message sinks.
* These require checking a sibling `role` property and cannot be expressed in MaD.
*/
API::Node getUserPromptNode() {
// contents: [{ role: "user", parts: [{ text: "..." }] }]
exists(API::Node msg |
msg =
clientRef()
.getMember("models")
.getMember(["generateContent", "generateContentStream"])
.getParameter(0)
.getMember("contents")
.getArrayElement() and
not msg.getMember("role").asSink().mayHaveStringValue(["system", "model"])
|
result = msg.getMember("parts").getArrayElement().getMember("text")
)
}
}

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@@ -1,287 +0,0 @@
/**
* Provides classes modeling security-relevant aspects of the `openAI-Node` package.
* See https://github.com/openai/openai-node
*
* Structurally typed sinks (instructions, prompt, input, etc.) have been moved to
* Models as Data: javascript/ql/lib/ext/openai.model.yml
*
* This file retains only role-filtered sinks that require inspecting a sibling
* `role` property, which MaD cannot express.
*/
private import javascript
/** Holds if `msg` is a message array element with a privileged role. */
private predicate isSystemOrDevMessage(API::Node msg) {
msg.getMember("role").asSink().mayHaveStringValue(["system", "developer", "assistant"])
}
module OpenAI {
/** Gets a reference to all OpenAI client instances. */
private API::Node allClients() {
result = API::moduleImport("openai").getInstance()
or
result = API::moduleImport("openai").getMember(["OpenAI", "AzureOpenAI"]).getInstance()
or
result =
API::moduleImport("@openai/guardrails")
.getMember(["GuardrailsOpenAI", "GuardrailsAzureOpenAI"])
.getMember("create")
.getReturn()
.getPromised()
}
/** Gets a guarded client that is clearly configured without input guardrails. */
private API::Node unprotectedGuardedClient() {
exists(API::Node createCall |
createCall =
API::moduleImport("@openai/guardrails")
.getMember(["GuardrailsOpenAI", "GuardrailsAzureOpenAI"])
.getMember("create") and
result = createCall.getReturn().getPromised() and
exists(createCall.getParameter(0).getMember("version")) and
not exists(
createCall.getParameter(0).getMember("input").getMember("guardrails").getArrayElement()
) and
not exists(
createCall.getParameter(0).getMember("pre_flight").getMember("guardrails").getArrayElement()
)
)
}
/** Gets a reference to all clients without input guardrails. */
private API::Node clientsNoGuardrails() {
result = API::moduleImport("openai").getInstance()
or
result = API::moduleImport("openai").getMember(["OpenAI", "AzureOpenAI"]).getInstance()
or
result = unprotectedGuardedClient()
}
/**
* Gets role-filtered system/developer/assistant message sinks.
* These require checking a sibling `role` property and cannot be expressed in MaD.
*/
API::Node getSystemOrAssistantPromptNode() {
// responses.create({ input: [{ role: "system"/"developer", content: "..." }] })
exists(API::Node msg |
msg =
allClients()
.getMember("responses")
.getMember("create")
.getParameter(0)
.getMember("input")
.getArrayElement() and
isSystemOrDevMessage(msg)
|
result = msg.getMember("content")
)
or
// chat.completions.create({ messages: [{ role: "system"/"developer", content: ... }] })
exists(API::Node msg, API::Node content |
msg =
allClients()
.getMember("chat")
.getMember("completions")
.getMember("create")
.getParameter(0)
.getMember("messages")
.getArrayElement() and
isSystemOrDevMessage(msg) and
content = msg.getMember("content")
|
result = content
or
result = content.getArrayElement().getMember("text")
)
or
// beta.threads.messages.create(threadId, { role: "system"/"developer", content: ... })
exists(API::Node msg |
msg =
allClients()
.getMember("beta")
.getMember("threads")
.getMember("messages")
.getMember("create")
.getParameter(1) and
isSystemOrDevMessage(msg)
|
result = msg.getMember("content")
)
}
/**
* Gets role-filtered user message sinks.
* These require checking a sibling `role` property and cannot be expressed in MaD.
*/
API::Node getUserPromptNode() {
// responses.create({ input: "string" })
result =
clientsNoGuardrails()
.getMember("responses")
.getMember("create")
.getParameter(0)
.getMember("input")
or
// responses.create({ input: [{ role: "user", content: ... }] })
exists(API::Node msg |
msg =
clientsNoGuardrails()
.getMember("responses")
.getMember("create")
.getParameter(0)
.getMember("input")
.getArrayElement() and
not isSystemOrDevMessage(msg)
|
result = msg.getMember("content")
)
or
// chat.completions.create({ messages: [{ role: "user", content: ... }] })
exists(API::Node msg, API::Node content |
msg =
clientsNoGuardrails()
.getMember("chat")
.getMember("completions")
.getMember("create")
.getParameter(0)
.getMember("messages")
.getArrayElement() and
not isSystemOrDevMessage(msg) and
content = msg.getMember("content")
|
result = content
or
result = content.getArrayElement().getMember("text")
)
or
// Legacy completions API: completions.create({ prompt: ... })
result =
clientsNoGuardrails()
.getMember("completions")
.getMember("create")
.getParameter(0)
.getMember("prompt")
or
// images.generate({ prompt: ... }) and images.edit({ prompt: ... })
result =
clientsNoGuardrails()
.getMember("images")
.getMember(["generate", "edit"])
.getParameter(0)
.getMember("prompt")
or
// beta.threads.messages.create(threadId, { role: "user", content: ... })
exists(API::Node msg |
msg =
clientsNoGuardrails()
.getMember("beta")
.getMember("threads")
.getMember("messages")
.getMember("create")
.getParameter(1) and
not isSystemOrDevMessage(msg)
|
result = msg.getMember("content")
)
or
// audio.transcriptions/translations.create({ prompt: ... })
result =
clientsNoGuardrails()
.getMember("audio")
.getMember(["transcriptions", "translations"])
.getMember("create")
.getParameter(0)
.getMember("prompt")
}
}
/**
* Provides models for agents SDK.
*
* See https://github.com/openai/openai-agents-js and
* https://github.com/openai/openai-guardrails-js.
*
* Structurally typed sinks have been moved to openai.model.yml.
* This module retains only role-filtered sinks, callback-based sinks, and
* unsafe agent detection that MaD cannot express.
*/
module AgentSDK {
API::Node moduleRef() {
result = API::moduleImport("@openai/agents")
or
result = API::moduleImport("@openai/guardrails")
}
/** Gets a reference to the top-level run() or Runner.run() functions. */
private API::Node run() {
result = moduleRef().getMember("run")
or
result = moduleRef().getMember("Runner").getInstance().getMember("run")
}
/**
* Gets role-filtered and callback-based system prompt sinks that MaD cannot express.
*/
API::Node getSystemOrAssistantPromptNode() {
// Agent({ instructions: (runContext) => returnValue }) — callback form
result = moduleRef()
.getMember("Agent")
.getParameter(0)
.getMember("instructions")
.getReturn()
or
// run(agent, [{ role: "system"/"developer", content: ... }])
exists(API::Node msg |
msg = run()
.getParameter(1)
.getArrayElement() and
isSystemOrDevMessage(msg)
|
result = msg.getMember("content")
)
}
/**
* Gets role-filtered user prompt sinks for run(agent, input).
* The string-input case is handled via MaD (openai.model.yml).
*/
API::Node getUserPromptNode() {
// run(agent, [{ role: "user", content: ... }])
exists(API::Node msg |
msg = run().getParameter(1).getArrayElement() and
not isSystemOrDevMessage(msg)
|
result = msg.getMember("content")
)
}
/**
* Gets an agent constructor config that visibly lacks input guardrails.
* Covers both native Agent({ inputGuardrails: [...] }) and
* GuardrailAgent.create({ input: { guardrails: [...] } }, ...).
*/
API::Node getUnsafeAgentNode() {
// new Agent({ name: '...', ... }) without inputGuardrails
result = moduleRef().getMember("Agent").getParameter(0) and
// Config is an inspectable object literal
(exists(result.getMember("name")) or exists(result.getMember("instructions"))) and
not exists(result.getMember("inputGuardrails").getArrayElement())
or
// GuardrailAgent.create(config, ...) without input/pre_flight guardrails
exists(API::Node createCall |
createCall =
moduleRef()
.getMember("GuardrailAgent")
.getMember("create") and
result = createCall.getParameter(0) and
exists(result.getMember("version")) and
not exists(
result.getMember("input").getMember("guardrails").getArrayElement()
) and
not exists(
result.getMember("pre_flight").getMember("guardrails").getArrayElement()
)
)
}
}

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@@ -1,114 +0,0 @@
/**
* Provides default sources, sinks and sanitizers for detecting
* "prompt injection"
* vulnerabilities, as well as extension points for adding your own.
*/
import javascript
private import semmle.javascript.dataflow.DataFlow
private import semmle.javascript.Concepts
private import semmle.javascript.security.dataflow.RemoteFlowSources
private import semmle.javascript.dataflow.internal.BarrierGuards
private import semmle.javascript.frameworks.data.ModelsAsData
private import experimental.semmle.javascript.frameworks.OpenAI
private import experimental.semmle.javascript.frameworks.Anthropic
private import experimental.semmle.javascript.frameworks.GoogleGenAI
/**
* Provides default sources, sinks and sanitizers for detecting
* "prompt injection"
* vulnerabilities, as well as extension points for adding your own.
*/
module SystemPromptInjection {
/**
* A data flow source for "prompt injection" vulnerabilities.
*/
abstract class Source extends DataFlow::Node { }
/**
* A data flow sink for "prompt injection" vulnerabilities.
*/
abstract class Sink extends DataFlow::Node { }
/**
* A sanitizer for "prompt injection" vulnerabilities.
*/
abstract class Sanitizer extends DataFlow::Node { }
/**
* An active threat-model source, considered as a flow source.
*/
private class ActiveThreatModelSourceAsSource extends Source, ActiveThreatModelSource {
}
/**
* A prompt to an AI model, considered as a flow sink.
*/
class AIPromptAsSink extends Sink {
AIPromptAsSink() { this = any(AIPrompt p).getAPrompt() }
}
private class SinkFromModel extends Sink {
SinkFromModel() {
this = ModelOutput::getASinkNode("system-prompt-injection").asSink()
}
}
private class PromptContentSink extends Sink {
PromptContentSink() {
this = OpenAI::getSystemOrAssistantPromptNode().asSink()
or
this = AgentSDK::getSystemOrAssistantPromptNode().asSink()
or
this = Anthropic::getSystemOrAssistantPromptNode().asSink()
or
this = GoogleGenAI::getSystemOrAssistantPromptNode().asSink()
}
}
private class ConstCompareAsSanitizerGuard extends Sanitizer {
ConstCompareAsSanitizerGuard()
{
this = DataFlow::MakeBarrierGuard<ConstCompareBarrierGuard>::getABarrierNode()
}
}
/**
* Content placed in a message with `role: "user"` is not a system prompt
* injection vector; it is intended user-role content.
*
* This prevents false positives when user input and system prompts are
* combined in the same message array (e.g. `[{role:"system", content: ...},
* {role:"user", content: tainted}]`) and taint would otherwise propagate
* through array operations to the system message.
*/
private class UserRoleMessageContentBarrier extends Sanitizer {
UserRoleMessageContentBarrier() {
exists(DataFlow::SourceNode obj |
obj.getAPropertySource("role").mayHaveStringValue("user") and
this = obj.getAPropertyWrite("content").getRhs()
)
}
}
/**
* A comparison with a constant, considered as a sanitizer-guard.
*/
private class ConstCompareBarrierGuard extends DataFlow::ValueNode
{
override EqualityTest astNode;
ConstCompareBarrierGuard()
{
astNode.hasOperands(_, any(ConstantString cs))
}
predicate blocksExpr(boolean outcome, Expr e) {
outcome = astNode.getPolarity() and
e = astNode.getLeftOperand() and
e = astNode.getAnOperand() and
not e instanceof ConstantString
}
}
}

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@@ -1,25 +0,0 @@
/**
* Provides a taint-tracking configuration for detecting "prompt injection" vulnerabilities.
*
* Note, for performance reasons: only import this file if
* `SystemPromptInjectionFlow::Configuration` is needed, otherwise
* `SystemPromptInjectionCustomizations` should be imported instead.
*/
private import javascript
import semmle.javascript.dataflow.DataFlow
import semmle.javascript.dataflow.TaintTracking
import SystemPromptInjectionCustomizations::SystemPromptInjection
private module SystemPromptInjectionConfig implements DataFlow::ConfigSig {
predicate isSource(DataFlow::Node node) { node instanceof Source }
predicate isSink(DataFlow::Node node) { node instanceof Sink }
predicate isBarrier(DataFlow::Node node) { node instanceof Sanitizer }
predicate observeDiffInformedIncrementalMode() { any() }
}
/** Global taint-tracking for detecting "prompt injection" vulnerabilities. */
module SystemPromptInjectionFlow = TaintTracking::Global<SystemPromptInjectionConfig>;

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@@ -11,9 +11,9 @@ private import semmle.javascript.Concepts
private import semmle.javascript.security.dataflow.RemoteFlowSources
private import semmle.javascript.dataflow.internal.BarrierGuards
private import semmle.javascript.frameworks.data.ModelsAsData
private import experimental.semmle.javascript.frameworks.OpenAI
private import experimental.semmle.javascript.frameworks.Anthropic
private import experimental.semmle.javascript.frameworks.GoogleGenAI
private import semmle.javascript.frameworks.OpenAI
private import semmle.javascript.frameworks.Anthropic
private import semmle.javascript.frameworks.GoogleGenAI
/**
* Provides default sources, sinks and sanitizers for detecting