mirror of
https://github.com/securego/gosec.git
synced 2024-12-25 20:15:54 +00:00
123 lines
3.9 KiB
Go
123 lines
3.9 KiB
Go
// (c) Copyright 2016 Hewlett Packard Enterprise Development LP
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package rules
|
|
|
|
import (
|
|
"go/ast"
|
|
"go/types"
|
|
|
|
"github.com/securego/gosec/v2"
|
|
"github.com/securego/gosec/v2/issue"
|
|
)
|
|
|
|
type subprocess struct {
|
|
issue.MetaData
|
|
gosec.CallList
|
|
}
|
|
|
|
func (r *subprocess) ID() string {
|
|
return r.MetaData.ID
|
|
}
|
|
|
|
// TODO(gm) The only real potential for command injection with a Go project
|
|
// is something like this:
|
|
//
|
|
// syscall.Exec("/bin/sh", []string{"-c", tainted})
|
|
//
|
|
// E.g. Input is correctly escaped but the execution context being used
|
|
// is unsafe. For example:
|
|
//
|
|
// syscall.Exec("echo", "foobar" + tainted)
|
|
func (r *subprocess) Match(n ast.Node, c *gosec.Context) (*issue.Issue, error) {
|
|
if node := r.ContainsPkgCallExpr(n, c, false); node != nil {
|
|
args := node.Args
|
|
if r.isContext(n, c) {
|
|
args = args[1:]
|
|
}
|
|
for _, arg := range args {
|
|
if ident, ok := arg.(*ast.Ident); ok {
|
|
obj := c.Info.ObjectOf(ident)
|
|
|
|
// need to cast and check whether it is for a variable ?
|
|
_, variable := obj.(*types.Var)
|
|
|
|
// .. indeed it is a variable then processing is different than a normal
|
|
// field assignment
|
|
if variable {
|
|
// skip the check when the declaration is not available
|
|
if ident.Obj == nil {
|
|
continue
|
|
}
|
|
switch ident.Obj.Decl.(type) {
|
|
case *ast.AssignStmt:
|
|
_, assignment := ident.Obj.Decl.(*ast.AssignStmt)
|
|
if variable && assignment {
|
|
if !gosec.TryResolve(ident, c) {
|
|
return c.NewIssue(n, r.ID(), "Subprocess launched with variable", issue.Medium, issue.High), nil
|
|
}
|
|
}
|
|
case *ast.Field:
|
|
_, field := ident.Obj.Decl.(*ast.Field)
|
|
if variable && field {
|
|
// check if the variable exist in the scope
|
|
vv, vvok := obj.(*types.Var)
|
|
|
|
if vvok && vv.Parent().Lookup(ident.Name) == nil {
|
|
return c.NewIssue(n, r.ID(), "Subprocess launched with variable", issue.Medium, issue.High), nil
|
|
}
|
|
}
|
|
case *ast.ValueSpec:
|
|
_, valueSpec := ident.Obj.Decl.(*ast.ValueSpec)
|
|
if variable && valueSpec {
|
|
if !gosec.TryResolve(ident, c) {
|
|
return c.NewIssue(n, r.ID(), "Subprocess launched with variable", issue.Medium, issue.High), nil
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else if !gosec.TryResolve(arg, c) {
|
|
// the arg is not a constant or a variable but instead a function call or os.Args[i]
|
|
return c.NewIssue(n, r.ID(), "Subprocess launched with a potential tainted input or cmd arguments", issue.Medium, issue.High), nil
|
|
}
|
|
}
|
|
}
|
|
return nil, nil
|
|
}
|
|
|
|
// isContext checks whether or not the node is a CommandContext call or not
|
|
// This is required in order to skip the first argument from the check.
|
|
func (r *subprocess) isContext(n ast.Node, ctx *gosec.Context) bool {
|
|
selector, indent, err := gosec.GetCallInfo(n, ctx)
|
|
if err != nil {
|
|
return false
|
|
}
|
|
if selector == "exec" && indent == "CommandContext" {
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
// NewSubproc detects cases where we are forking out to an external process
|
|
func NewSubproc(id string, _ gosec.Config) (gosec.Rule, []ast.Node) {
|
|
rule := &subprocess{issue.MetaData{ID: id}, gosec.NewCallList()}
|
|
rule.Add("os/exec", "Command")
|
|
rule.Add("os/exec", "CommandContext")
|
|
rule.Add("syscall", "Exec")
|
|
rule.Add("syscall", "ForkExec")
|
|
rule.Add("syscall", "StartProcess")
|
|
rule.Add("golang.org/x/sys/execabs", "Command")
|
|
rule.Add("golang.org/x/sys/execabs", "CommandContext")
|
|
return rule, []ast.Node{(*ast.CallExpr)(nil)}
|
|
}
|