diff options
Diffstat (limited to 'meta/recipes-core/meta/cve-update-nvd2-native.bb')
| -rw-r--r-- | meta/recipes-core/meta/cve-update-nvd2-native.bb | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/meta/recipes-core/meta/cve-update-nvd2-native.bb b/meta/recipes-core/meta/cve-update-nvd2-native.bb new file mode 100644 index 0000000000..1901641965 --- /dev/null +++ b/meta/recipes-core/meta/cve-update-nvd2-native.bb @@ -0,0 +1,377 @@ +SUMMARY = "Updates the NVD CVE database" +LICENSE = "MIT" + +# Important note: +# This product uses the NVD API but is not endorsed or certified by the NVD. + +INHIBIT_DEFAULT_DEPS = "1" + +inherit native + +deltask do_unpack +deltask do_patch +deltask do_configure +deltask do_compile +deltask do_install +deltask do_populate_sysroot + +NVDCVE_URL ?= "https://services.nvd.nist.gov/rest/json/cves/2.0" + +# If you have a NVD API key (https://nvd.nist.gov/developers/request-an-api-key) +# then setting this to get higher rate limits. +NVDCVE_API_KEY ?= "" + +# CVE database update interval, in seconds. By default: once a day (24*60*60). +# Use 0 to force the update +# Use a negative value to skip the update +CVE_DB_UPDATE_INTERVAL ?= "86400" + +# CVE database incremental update age threshold, in seconds. If the database is +# older than this threshold, do a full re-download, else, do an incremental +# update. By default: the maximum allowed value from NVD: 120 days (120*24*60*60) +# Use 0 to force a full download. +CVE_DB_INCR_UPDATE_AGE_THRES ?= "10368000" + +# Number of attempts for each http query to nvd server before giving up +CVE_DB_UPDATE_ATTEMPTS ?= "5" + +CVE_DB_TEMP_FILE ?= "${CVE_CHECK_DB_DIR}/temp_nvdcve_2.db" + +python () { + if not bb.data.inherits_class("cve-check", d): + raise bb.parse.SkipRecipe("Skip recipe when cve-check class is not loaded.") +} + +python do_fetch() { + """ + Update NVD database with API 2.0 + """ + import bb.utils + import bb.progress + import shutil + + bb.utils.export_proxies(d) + + db_file = d.getVar("CVE_CHECK_DB_FILE") + db_dir = os.path.dirname(db_file) + db_tmp_file = d.getVar("CVE_DB_TEMP_FILE") + + cleanup_db_download(db_file, db_tmp_file) + # By default let's update the whole database (since time 0) + database_time = 0 + + # The NVD database changes once a day, so no need to update more frequently + # Allow the user to force-update + try: + import time + update_interval = int(d.getVar("CVE_DB_UPDATE_INTERVAL")) + if update_interval < 0: + bb.note("CVE database update skipped") + return + if time.time() - os.path.getmtime(db_file) < update_interval: + bb.note("CVE database recently updated, skipping") + return + database_time = os.path.getmtime(db_file) + + except OSError: + pass + + bb.utils.mkdirhier(db_dir) + if os.path.exists(db_file): + shutil.copy2(db_file, db_tmp_file) + + if update_db_file(db_tmp_file, d, database_time) == True: + # Update downloaded correctly, can swap files + shutil.move(db_tmp_file, db_file) + else: + # Update failed, do not modify the database + bb.warn("CVE database update failed") + os.remove(db_tmp_file) +} + +do_fetch[lockfiles] += "${CVE_CHECK_DB_FILE_LOCK}" +do_fetch[file-checksums] = "" +do_fetch[vardeps] = "" + +def cleanup_db_download(db_file, db_tmp_file): + """ + Cleanup the download space from possible failed downloads + """ + + # Clean up the updates done on the main file + # Remove it only if a journal file exists - it means a complete re-download + if os.path.exists("{0}-journal".format(db_file)): + # If a journal is present the last update might have been interrupted. In that case, + # just wipe any leftovers and force the DB to be recreated. + os.remove("{0}-journal".format(db_file)) + + if os.path.exists(db_file): + os.remove(db_file) + + # Clean-up the temporary file downloads, we can remove both journal + # and the temporary database + if os.path.exists("{0}-journal".format(db_tmp_file)): + # If a journal is present the last update might have been interrupted. In that case, + # just wipe any leftovers and force the DB to be recreated. + os.remove("{0}-journal".format(db_tmp_file)) + + if os.path.exists(db_tmp_file): + os.remove(db_tmp_file) + +def nvd_request_wait(attempt, min_wait): + return min ( ( (2 * attempt) + min_wait ) , 30) + +def nvd_request_next(url, attempts, api_key, args, min_wait): + """ + Request next part of the NVD database + NVD API documentation: https://nvd.nist.gov/developers/vulnerabilities + """ + + import urllib.request + import urllib.parse + import gzip + import http + import time + + request = urllib.request.Request(url + "?" + urllib.parse.urlencode(args)) + if api_key: + request.add_header("apiKey", api_key) + bb.note("Requesting %s" % request.full_url) + + for attempt in range(attempts): + try: + r = urllib.request.urlopen(request) + + if (r.headers['content-encoding'] == 'gzip'): + buf = r.read() + raw_data = gzip.decompress(buf) + else: + raw_data = r.read().decode("utf-8") + + r.close() + + except Exception as e: + wait_time = nvd_request_wait(attempt, min_wait) + bb.note("CVE database: received error (%s)" % (e)) + bb.note("CVE database: retrying download after %d seconds. attempted (%d/%d)" % (wait_time, attempt+1, attempts)) + time.sleep(wait_time) + pass + else: + return raw_data + else: + # We failed at all attempts + return None + +def update_db_file(db_tmp_file, d, database_time): + """ + Update the given database file + """ + import bb.utils, bb.progress + import datetime + import sqlite3 + import json + + # Connect to database + conn = sqlite3.connect(db_tmp_file) + initialize_db(conn) + + req_args = {'startIndex' : 0} + + incr_update_threshold = int(d.getVar("CVE_DB_INCR_UPDATE_AGE_THRES")) + if database_time != 0: + database_date = datetime.datetime.fromtimestamp(database_time, tz=datetime.timezone.utc) + today_date = datetime.datetime.now(tz=datetime.timezone.utc) + delta = today_date - database_date + if incr_update_threshold == 0: + bb.note("CVE database: forced full update") + elif delta < datetime.timedelta(seconds=incr_update_threshold): + bb.note("CVE database: performing partial update") + # The maximum range for time is 120 days + if delta > datetime.timedelta(days=120): + bb.error("CVE database: Trying to do an incremental update on a larger than supported range") + req_args['lastModStartDate'] = database_date.isoformat() + req_args['lastModEndDate'] = today_date.isoformat() + else: + bb.note("CVE database: file too old, forcing a full update") + else: + bb.note("CVE database: no preexisting database, do a full download") + + with bb.progress.ProgressHandler(d) as ph, open(os.path.join(d.getVar("TMPDIR"), 'cve_check'), 'a') as cve_f: + + bb.note("Updating entries") + index = 0 + url = d.getVar("NVDCVE_URL") + api_key = d.getVar("NVDCVE_API_KEY") or None + attempts = int(d.getVar("CVE_DB_UPDATE_ATTEMPTS")) + + # Recommended by NVD + wait_time = 6 + if api_key: + wait_time = 2 + + while True: + req_args['startIndex'] = index + raw_data = nvd_request_next(url, attempts, api_key, req_args, wait_time) + if raw_data is None: + # We haven't managed to download data + return False + + data = json.loads(raw_data) + + index = data["startIndex"] + total = data["totalResults"] + per_page = data["resultsPerPage"] + bb.note("Got %d entries" % per_page) + for cve in data["vulnerabilities"]: + update_db(conn, cve) + + index += per_page + ph.update((float(index) / (total+1)) * 100) + if index >= total: + break + + # Recommended by NVD + time.sleep(wait_time) + + # Update success, set the date to cve_check file. + cve_f.write('CVE database update : %s\n\n' % datetime.date.today()) + + conn.commit() + conn.close() + return True + +def initialize_db(conn): + with conn: + c = conn.cursor() + + c.execute("CREATE TABLE IF NOT EXISTS META (YEAR INTEGER UNIQUE, DATE TEXT)") + + c.execute("CREATE TABLE IF NOT EXISTS NVD (ID TEXT UNIQUE, SUMMARY TEXT, \ + SCOREV2 TEXT, SCOREV3 TEXT, MODIFIED INTEGER, VECTOR TEXT, VECTORSTRING TEXT)") + + c.execute("CREATE TABLE IF NOT EXISTS PRODUCTS (ID TEXT, \ + VENDOR TEXT, PRODUCT TEXT, VERSION_START TEXT, OPERATOR_START TEXT, \ + VERSION_END TEXT, OPERATOR_END TEXT)") + c.execute("CREATE INDEX IF NOT EXISTS PRODUCT_ID_IDX on PRODUCTS(ID);") + + c.close() + +def parse_node_and_insert(conn, node, cveId): + + def cpe_generator(): + for cpe in node.get('cpeMatch', ()): + if not cpe['vulnerable']: + return + cpe23 = cpe.get('criteria') + if not cpe23: + return + cpe23 = cpe23.split(':') + if len(cpe23) < 6: + return + vendor = cpe23[3] + product = cpe23[4] + version = cpe23[5] + + if cpe23[6] == '*' or cpe23[6] == '-': + version_suffix = "" + else: + version_suffix = "_" + cpe23[6] + + if version != '*' and version != '-': + # Version is defined, this is a '=' match + yield [cveId, vendor, product, version + version_suffix, '=', '', ''] + elif version == '-': + # no version information is available + yield [cveId, vendor, product, version, '', '', ''] + else: + # Parse start version, end version and operators + op_start = '' + op_end = '' + v_start = '' + v_end = '' + + if 'versionStartIncluding' in cpe: + op_start = '>=' + v_start = cpe['versionStartIncluding'] + + if 'versionStartExcluding' in cpe: + op_start = '>' + v_start = cpe['versionStartExcluding'] + + if 'versionEndIncluding' in cpe: + op_end = '<=' + v_end = cpe['versionEndIncluding'] + + if 'versionEndExcluding' in cpe: + op_end = '<' + v_end = cpe['versionEndExcluding'] + + if op_start or op_end or v_start or v_end: + yield [cveId, vendor, product, v_start, op_start, v_end, op_end] + else: + # This is no version information, expressed differently. + # Save processing by representing as -. + yield [cveId, vendor, product, '-', '', '', ''] + + conn.executemany("insert into PRODUCTS values (?, ?, ?, ?, ?, ?, ?)", cpe_generator()).close() + +def update_db(conn, elt): + """ + Update a single entry in the on-disk database + """ + + accessVector = None + vectorString = None + cveId = elt['cve']['id'] + if elt['cve']['vulnStatus'] == "Rejected": + c = conn.cursor() + c.execute("delete from PRODUCTS where ID = ?;", [cveId]) + c.execute("delete from NVD where ID = ?;", [cveId]) + c.close() + return + cveDesc = "" + for desc in elt['cve']['descriptions']: + if desc['lang'] == 'en': + cveDesc = desc['value'] + date = elt['cve']['lastModified'] + try: + accessVector = elt['cve']['metrics']['cvssMetricV2'][0]['cvssData']['accessVector'] + vectorString = elt['cve']['metrics']['cvssMetricV2'][0]['cvssData']['vectorString'] + cvssv2 = elt['cve']['metrics']['cvssMetricV2'][0]['cvssData']['baseScore'] + except KeyError: + cvssv2 = 0.0 + cvssv3 = None + try: + accessVector = accessVector or elt['cve']['metrics']['cvssMetricV30'][0]['cvssData']['attackVector'] + vectorString = vectorString or elt['cve']['metrics']['cvssMetricV30'][0]['cvssData']['vectorString'] + cvssv3 = elt['cve']['metrics']['cvssMetricV30'][0]['cvssData']['baseScore'] + except KeyError: + pass + try: + accessVector = accessVector or elt['cve']['metrics']['cvssMetricV31'][0]['cvssData']['attackVector'] + vectorString = vectorString or elt['cve']['metrics']['cvssMetricV31'][0]['cvssData']['vectorString'] + cvssv3 = cvssv3 or elt['cve']['metrics']['cvssMetricV31'][0]['cvssData']['baseScore'] + except KeyError: + pass + accessVector = accessVector or "UNKNOWN" + vectorString = vectorString or "UNKNOWN" + cvssv3 = cvssv3 or 0.0 + + conn.execute("insert or replace into NVD values (?, ?, ?, ?, ?, ?, ?)", + [cveId, cveDesc, cvssv2, cvssv3, date, accessVector, vectorString]).close() + + try: + # Remove any pre-existing CVE configuration. Even for partial database + # update, those will be repopulated. This ensures that old + # configuration is not kept for an updated CVE. + conn.execute("delete from PRODUCTS where ID = ?", [cveId]).close() + for config in elt['cve']['configurations']: + # This is suboptimal as it doesn't handle AND/OR and negate, but is better than nothing + for node in config["nodes"]: + parse_node_and_insert(conn, node, cveId) + except KeyError: + bb.note("CVE %s has no configurations" % cveId) + +do_fetch[nostamp] = "1" + +EXCLUDE_FROM_WORLD = "1" |