Security

Security/CompoundHash

| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed

Pending

Yes

No

1.28

-

Checks for implementations of the hash method which combine values using custom logic instead of delegating to Array#hash.

Manually combining hashes is error prone and hard to follow, especially when there are many values. Poor implementations may also introduce performance or security concerns if they are prone to collisions. Delegating to Array#hash is clearer, faster, and safer.

Safety

This cop may be unsafe if the application logic depends on the hash value, however this is inadvisable anyway.

Examples

# bad
def hash
  @foo ^ @bar
end

# good
def hash
  [@foo, @bar].hash
end

Security/Eval

| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed

Enabled

Yes

No

0.47

-

Checks for the use of Kernel#eval and Binding#eval.

Examples

# bad

eval(something)
binding.eval(something)

Security/IoMethods

| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed

Pending

No

Yes (Unsafe)

1.22

-

Checks for the first argument to IO.read, IO.binread, IO.write, IO.binwrite, IO.foreach, and IO.readlines.

If argument starts with a pipe character ('|') and the receiver is the IO class, a subprocess is created in the same way as Kernel#open, and its output is returned. Kernel#open may allow unintentional command injection, which is the reason these IO methods are a security risk. Consider to use File.read to disable the behavior of subprocess invocation.

Safety

This cop is unsafe because false positive will occur if the variable passed as the first argument is a command that is not a file path.

Examples

# bad
IO.read(path)
IO.read('path')

# good
File.read(path)
File.read('path')
IO.read('| command') # Allow intentional command invocation.

Security/JSONLoad

| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed

Enabled

Yes

Yes (Unsafe)

0.43

1.22

Checks for the use of JSON class methods which have potential security issues.

Safety

This cop’s autocorrection is unsafe because it’s potentially dangerous. If using a stream, like JSON.load(open('file')), it will need to call #read manually, like JSON.parse(open('file').read). If reading single values (rather than proper JSON objects), like JSON.load('false'), it will need to pass the quirks_mode: true option, like JSON.parse('false', quirks_mode: true). Other similar issues may apply.

Examples

# bad
JSON.load("{}")
JSON.restore("{}")

# good
JSON.parse("{}")

References

Security/MarshalLoad

| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed

Enabled

Yes

No

0.47

-

Checks for the use of Marshal class methods which have potential security issues leading to remote code execution when loading from an untrusted source.

Examples

# bad
Marshal.load("{}")
Marshal.restore("{}")

# good
Marshal.dump("{}")

# okish - deep copy hack
Marshal.load(Marshal.dump({}))

References

Security/Open

| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed

Enabled

No

No

0.53

1.0

Checks for the use of Kernel#open and URI.open with dynamic data.

Kernel#open and URI.open enable not only file access but also process invocation by prefixing a pipe symbol (e.g., open("| ls")). So, it may lead to a serious security risk by using variable input to the argument of Kernel#open and URI.open. It would be better to use File.open, IO.popen or URI.parse#open explicitly.

open and URI.open with literal strings are not flagged by this cop.

Safety

This cop could register false positives if open is redefined in a class and then used without a receiver in that class.

Examples

# bad
open(something)
open("| #{something}")
URI.open(something)

# good
File.open(something)
IO.popen(something)
URI.parse(something).open

# good (literal strings)
open("foo.text")
open("| foo")
URI.open("http://example.com")

Security/YAMLLoad

| Enabled by default | Safe | Supports autocorrection | Version Added | Version Changed

Enabled

Yes

Yes (Unsafe)

0.47

-

Checks for the use of YAML class methods which have potential security issues leading to remote code execution when loading from an untrusted source.

Ruby 3.1+ (Psych 4) uses Psych.load as Psych.safe_load by default.

Safety

The behavior of the code might change depending on what was in the YAML payload, since YAML.safe_load is more restrictive.

Examples

# bad
YAML.load("--- !ruby/object:Foo {}") # Psych 3 is unsafe by default

# good
YAML.safe_load("--- !ruby/object:Foo {}", [Foo])                    # Ruby 2.5  (Psych 3)
YAML.safe_load("--- !ruby/object:Foo {}", permitted_classes: [Foo]) # Ruby 3.0- (Psych 3)
YAML.load("--- !ruby/object:Foo {}", permitted_classes: [Foo])      # Ruby 3.1+ (Psych 4)
YAML.dump(foo)

References