/**

* @name Uncontrolled data in SQL query

* @description Including user-supplied data in a SQL query without

* neutralizing special elements can make code vulnerable

* to SQL Injection.

* @kind path-problem

* @problem.severity error

* @security-severity 8.8

* @precision high

* @id cpp/sql-injection

* @tags security

* external/cwe/cwe-089

*/

import cpp

import semmle.code.cpp.security.Security

import semmle.code.cpp.security.FlowSources

import semmle.code.cpp.security.FunctionWithWrappers

import semmle.code.cpp.ir.IR

import semmle.code.cpp.ir.dataflow.TaintTracking

import SqlTainted::PathGraph

class SqlLikeFunction extends FunctionWithWrappers {

SqlLikeFunction() { sqlArgument(this.getName(), _) }

override predicate interestingArg(int arg) { sqlArgument(this.getName(), arg) }

}

Expr asSinkExpr(DataFlow::Node node) {

result = node.asIndirectArgument()

or

// We want the conversion so we only get one node for the expression

result = node.asExpr()

}

module SqlTaintedConfig implements DataFlow::ConfigSig {

predicate isSource(DataFlow::Node node) { node instanceof FlowSource }

predicate isSink(DataFlow::Node node) {

exists(SqlLikeFunction runSql | runSql.outermostWrapperFunctionCall(asSinkExpr(node), _))

or

// sink defined using models-as-data

sinkNode(node, "sql-injection")

}

predicate isBarrier(DataFlow::Node node) {

node.asExpr().getUnspecifiedType() instanceof IntegralType

or

exists(SqlBarrierFunction sql, int arg, FunctionInput input |

node.asIndirectArgument() = sql.getACallToThisFunction().getArgument(arg) and

input.isParameterDeref(arg) and

sql.barrierSqlArgument(input, _)

)

or

// barrier defined using models-as-data

barrierNode(node, "sql-injection")

}

predicate observeDiffInformedIncrementalMode() { any() }

Location getASelectedSinkLocation(DataFlow::Node sink) {

exists(Expr taintedArg | result = [taintedArg.getLocation(), sink.getLocation()] |

taintedArg = asSinkExpr(sink)

)

}

}

module SqlTainted = TaintTracking::Global<SqlTaintedConfig>;

from

Expr taintedArg, FlowSource taintSource, SqlTainted::PathNode sourceNode,

SqlTainted::PathNode sinkNode, string extraText

where

(

exists(SqlLikeFunction runSql, string callChain |

runSql.outermostWrapperFunctionCall(taintedArg, callChain) and

extraText = " and then passed to " + callChain

)

or

sinkNode(sinkNode.getNode(), "sql-injection") and

extraText = ""

) and

SqlTainted::flowPath(sourceNode, sinkNode) and

taintedArg = asSinkExpr(sinkNode.getNode()) and

taintSource = sourceNode.getNode()

select taintedArg, sourceNode, sinkNode,

"This argument to a SQL query function is derived from $@" + extraText + ".", taintSource,

"user input (" + taintSource.getSourceType() + ")"