CVE-2023-47116 (Python, published 2024-01-31T17:15Z)
Description: value: Label Studio is a popular open source data labeling tool. The vulnerability affects all versions of Label Studio prior to 1.11.0 and was tested on version 1.8.2. Label Studio's SSRF protections that can be enabled by setting the `SSRF_PROTECTION_ENABLED` environment variable can be bypassed to access internal web servers. This is because the current SSRF validation is done by executing a single DNS lookup to verify that the IP address is not in an excluded subnet range. This protection can be bypassed by either using HTTP redirection or performing a DNS rebinding attack.
Severity: nan (CVSS v3 base score: 5.3)
Weakness: CWE-918 \u2014 Server-Side Request Forgery (SSRF)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Repository: https://github.com/HumanSignal/label-studio
Files changed:
label_studio/core/settings/base.py
label_studio/core/utils/io.py
label_studio/tests/data_import/test_uploader.py
Commit message: fix: LEAP-396: More exhaustative IP validation for SSRF defenses, plus user configurability (#5316)

* fix: LEAP-396: More exhaustative IP validation for SSRF, plus user configurability

* unbotch

* fix test

* more testing

* fix false positive finding from Bandit

Vulnerable code:
    """Checks if an IP is local/private.
    if ip == '0.0.0.0':  # nosec
        raise InvalidUploadUrlError
    local_subnets = [
        '127.0.0.0/8',
        '10.0.0.0/8',
        '172.16.0.0/12',
        '192.168.0.0/16',
    for subnet in local_subnets:
            raise InvalidUploadUrlError
            assert 'The provided URL was not valid.' in str(e.value)

Fixed code:
USE_DEFAULT_BANNED_SUBNETS = get_bool_env('USE_DEFAULT_BANNED_SUBNETS', True)
USER_ADDITIONAL_BANNED_SUBNETS = get_env_list('USER_ADDITIONAL_BANNED_SUBNETS', default=[])
    """If settings.USE_DEFAULT_BANNED_SUBNETS is True, this function checks
    if an IP is reserved for any of the reasons in
    https://en.wikipedia.org/wiki/Reserved_IP_addresses
    and raises an exception if so. Additionally, if settings.USER_ADDITIONAL_BANNED_SUBNETS
    is set, it will also check against those subnets.

    If settings.USE_DEFAULT_BANNED_SUBNETS is False, this function will only check
    the IP against settings.USER_ADDITIONAL_BANNED_SUBNETS. Turning off the default
    subnets is **risky** and should only be done if you know what you're doing.
    default_banned_subnets = [
        '0.0.0.0/8',  # current network
        '10.0.0.0/8',  # private network
        '100.64.0.0/10',  # shared address space
        '127.0.0.0/8',  # loopback
        '169.254.0.0/16',  # link-local
        '172.16.0.0/12',  # private network
        '192.0.0.0/24',  # IETF protocol assignments
        '192.0.2.0/24',  # TEST-NET-1
        '192.88.99.0/24',  # Reserved, formerly ipv6 to ipv4 relay
        '192.168.0.0/16',  # private network
        '198.18.0.0/15',  # network interconnect device benchmark testing
        '198.51.100.0/24',  # TEST-NET-2
        '203.0.113.0/24',  # TEST-NET-3
        '224.0.0.0/4',  # multicast
        '233.252.0.0/24',  # MCAST-TEST-NET
        '240.0.0.0/4',  # reserved for future use
        '255.255.255.255/32',  # limited broadcast
        '::/128',  # unspecified address
        '::1/128',  # loopback
        '::ffff:0:0/96',  # IPv4-mapped address
        '::ffff:0:0:0/96',  # IPv4-translated address
        '64:ff9b::/96',  # IPv4/IPv6 translation
        '64:ff9b:1::/48',  # IPv4/IPv6 translation
        '100::/64',  # discard prefix
        '2001:0000::/32',  # Teredo tunneling
        '2001:20::/28',  # ORCHIDv2
        '2001:db8::/32',  # documentation
        '2002::/16',  # 6to4
        'fc00::/7',  # unique local
        'fe80::/10',  # link-local
        'ff00::/8',  # multicast
    ]
    banned_subnets = [
        *(default_banned_subnets if settings.USE_DEFAULT_BANNED_SUBNETS else []),
        *(settings.USER_ADDITIONAL_BANNED_SUBNETS or []),
    for subnet in banned_subnets:
            raise InvalidUploadUrlError(f'URL resolves to a reserved network address (block: {subnet})')
            assert 'URL resolves to a reserved network address (block: 127.0.0.0/8)' in str(e.value)

        def test_user_specified_block(self, project, settings):
            settings.SSRF_PROTECTION_ENABLED = True
            settings.USER_ADDITIONAL_BANNED_SUBNETS = ['1.2.3.4']
            request = MockedRequest(url='http://validurl.com')

            # Mock the necessary parts of the response object
            mock_response = Mock()
            mock_response.raw._connection.sock.getpeername.return_value = ('1.2.3.4', 8080)

            # Patch the requests.get call in the data_import.uploader module
            with mock.patch('core.utils.io.requests.get', return_value=mock_response), pytest.raises(
                ValidationError
            ) as e:
                load_tasks(request, project)
            assert 'URL resolves to a reserved network address (block: 1.2.3.4)' in str(e.value)

            mock_response.raw._connection.sock.getpeername.return_value = ('198.51.100.0', 8080)
            with mock.patch('core.utils.io.requests.get', return_value=mock_response), pytest.raises(
                ValidationError
            ) as e:
                load_tasks(request, project)
            assert 'URL resolves to a reserved network address (block: 198.51.100.0/24)' in str(e.value)

        def test_user_specified_block_without_default(self, project, settings):
            settings.SSRF_PROTECTION_ENABLED = True
            settings.USER_ADDITIONAL_BANNED_SUBNETS = ['1.2.3.4']
            settings.USE_DEFAULT_BANNED_SUBNETS = False
            request = MockedRequest(url='http://validurl.com')

            # Mock the necessary parts of the response object
            mock_response = Mock()
            mock_response.raw._connection.sock.getpeername.return_value = ('1.2.3.4', 8080)

            # Patch the requests.get call in the data_import.uploader module
            with mock.patch('core.utils.io.requests.get', return_value=mock_response), pytest.raises(
                ValidationError
            ) as e:
                load_tasks(request, project)
            assert 'URL resolves to a reserved network address (block: 1.2.3.4)' in str(e.value)

            mock_response.raw._connection.sock.getpeername.return_value = ('198.51.100.0', 8080)
            with mock.patch('core.utils.io.requests.get', return_value=mock_response), pytest.raises(
                ValidationError
            ) as e:
                load_tasks(request, project)
            assert "'Mock' object is not subscriptable" in str(e.value)  # validate ip did not raise exception