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Diffstat (limited to 'meta/classes/cve-check.bbclass')
| -rw-r--r-- | meta/classes/cve-check.bbclass | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/meta/classes/cve-check.bbclass b/meta/classes/cve-check.bbclass new file mode 100644 index 0000000000..079d09a76f --- /dev/null +++ b/meta/classes/cve-check.bbclass @@ -0,0 +1,347 @@ +# This class is used to check recipes against public CVEs. +# +# In order to use this class just inherit the class in the +# local.conf file and it will add the cve_check task for +# every recipe. The task can be used per recipe, per image, +# or using the special cases "world" and "universe". The +# cve_check task will print a warning for every unpatched +# CVE found and generate a file in the recipe WORKDIR/cve +# directory. If an image is build it will generate a report +# in DEPLOY_DIR_IMAGE for all the packages used. +# +# Example: +# bitbake -c cve_check openssl +# bitbake core-image-sato +# bitbake -k -c cve_check universe +# +# DISCLAIMER +# +# This class/tool is meant to be used as support and not +# the only method to check against CVEs. Running this tool +# doesn't guarantee your packages are free of CVEs. + +# The product name that the CVE database uses defaults to BPN, but may need to +# be overriden per recipe (for example tiff.bb sets CVE_PRODUCT=libtiff). +CVE_PRODUCT ??= "${BPN}" +CVE_VERSION ??= "${PV}" + +CVE_CHECK_DB_DIR ?= "${DL_DIR}/CVE_CHECK" +CVE_CHECK_DB_FILE ?= "${CVE_CHECK_DB_DIR}/nvdcve_1.1.db" +CVE_CHECK_DB_FILE_LOCK ?= "${CVE_CHECK_DB_FILE}.lock" + +CVE_CHECK_LOG ?= "${T}/cve.log" +CVE_CHECK_TMP_FILE ?= "${TMPDIR}/cve_check" +CVE_CHECK_SUMMARY_DIR ?= "${LOG_DIR}/cve" +CVE_CHECK_SUMMARY_FILE_NAME ?= "cve-summary" +CVE_CHECK_SUMMARY_FILE ?= "${CVE_CHECK_SUMMARY_DIR}/${CVE_CHECK_SUMMARY_FILE_NAME}" + +CVE_CHECK_DIR ??= "${DEPLOY_DIR}/cve" +CVE_CHECK_RECIPE_FILE ?= "${CVE_CHECK_DIR}/${PN}" +CVE_CHECK_MANIFEST ?= "${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.cve" +CVE_CHECK_COPY_FILES ??= "1" +CVE_CHECK_CREATE_MANIFEST ??= "1" + +CVE_CHECK_REPORT_PATCHED ??= "1" + +# Whitelist for packages (PN) +CVE_CHECK_SKIP_RECIPE ?= "" + +# Whitelist for CVE. If a CVE is found, then it is considered patched. +# The value is a string containing space separated CVE values: +# +# CVE_CHECK_IGNORE = 'CVE-2014-2524 CVE-2018-1234' +# +CVE_CHECK_IGNORE ?= "" + +# Layers to be excluded +CVE_CHECK_LAYER_EXCLUDELIST ??= "" + +# Layers to be included +CVE_CHECK_LAYER_INCLUDELIST ??= "" + + +# set to "alphabetical" for version using single alphabetical character as increment release +CVE_VERSION_SUFFIX ??= "" + +python cve_save_summary_handler () { + import shutil + import datetime + + cve_tmp_file = d.getVar("CVE_CHECK_TMP_FILE") + + cve_summary_name = d.getVar("CVE_CHECK_SUMMARY_FILE_NAME") + cvelogpath = d.getVar("CVE_CHECK_SUMMARY_DIR") + bb.utils.mkdirhier(cvelogpath) + + timestamp = datetime.datetime.now().strftime('%Y%m%d%H%M%S') + cve_summary_file = os.path.join(cvelogpath, "%s-%s.txt" % (cve_summary_name, timestamp)) + + if os.path.exists(cve_tmp_file): + shutil.copyfile(cve_tmp_file, cve_summary_file) + + if cve_summary_file and os.path.exists(cve_summary_file): + cvefile_link = os.path.join(cvelogpath, cve_summary_name) + + if os.path.exists(os.path.realpath(cvefile_link)): + os.remove(cvefile_link) + os.symlink(os.path.basename(cve_summary_file), cvefile_link) +} + +addhandler cve_save_summary_handler +cve_save_summary_handler[eventmask] = "bb.event.BuildCompleted" + +python do_cve_check () { + """ + Check recipe for patched and unpatched CVEs + """ + from oe.cve_check import get_patched_cves + + if os.path.exists(d.getVar("CVE_CHECK_DB_FILE")): + try: + patched_cves = get_patched_cves(d) + except FileNotFoundError: + bb.fatal("Failure in searching patches") + whitelisted, patched, unpatched = check_cves(d, patched_cves) + if patched or unpatched: + cve_data = get_cve_info(d, patched + unpatched) + cve_write_data(d, patched, unpatched, whitelisted, cve_data) + else: + bb.note("No CVE database found, skipping CVE check") + +} + +addtask cve_check before do_build after do_fetch +do_cve_check[depends] = "cve-update-db-native:do_fetch" +do_cve_check[nostamp] = "1" + +python cve_check_cleanup () { + """ + Delete the file used to gather all the CVE information. + """ + bb.utils.remove(e.data.getVar("CVE_CHECK_TMP_FILE")) +} + +addhandler cve_check_cleanup +cve_check_cleanup[eventmask] = "bb.cooker.CookerExit" + +python cve_check_write_rootfs_manifest () { + """ + Create CVE manifest when building an image + """ + + import shutil + + if d.getVar("CVE_CHECK_COPY_FILES") == "1": + deploy_file = d.getVar("CVE_CHECK_RECIPE_FILE") + if os.path.exists(deploy_file): + bb.utils.remove(deploy_file) + + if os.path.exists(d.getVar("CVE_CHECK_TMP_FILE")): + bb.note("Writing rootfs CVE manifest") + deploy_dir = d.getVar("DEPLOY_DIR_IMAGE") + link_name = d.getVar("IMAGE_LINK_NAME") + manifest_name = d.getVar("CVE_CHECK_MANIFEST") + cve_tmp_file = d.getVar("CVE_CHECK_TMP_FILE") + + bb.utils.mkdirhier(os.path.dirname(manifest_name)) + shutil.copyfile(cve_tmp_file, manifest_name) + + if manifest_name and os.path.exists(manifest_name): + manifest_link = os.path.join(deploy_dir, "%s.cve" % link_name) + # If we already have another manifest, update symlinks + if os.path.exists(os.path.realpath(manifest_link)): + os.remove(manifest_link) + os.symlink(os.path.basename(manifest_name), manifest_link) + bb.plain("Image CVE report stored in: %s" % manifest_name) +} + +ROOTFS_POSTPROCESS_COMMAND:prepend = "${@'cve_check_write_rootfs_manifest; ' if d.getVar('CVE_CHECK_CREATE_MANIFEST') == '1' else ''}" +do_rootfs[recrdeptask] += "${@'do_cve_check' if d.getVar('CVE_CHECK_CREATE_MANIFEST') == '1' else ''}" + +def check_cves(d, patched_cves): + """ + Connect to the NVD database and find unpatched cves. + """ + from oe.cve_check import Version + + pn = d.getVar("PN") + real_pv = d.getVar("PV") + suffix = d.getVar("CVE_VERSION_SUFFIX") + + cves_unpatched = [] + # CVE_PRODUCT can contain more than one product (eg. curl/libcurl) + products = d.getVar("CVE_PRODUCT").split() + # If this has been unset then we're not scanning for CVEs here (for example, image recipes) + if not products: + return ([], [], []) + pv = d.getVar("CVE_VERSION").split("+git")[0] + + # If the recipe has been whitelisted we return empty lists + if pn in d.getVar("CVE_CHECK_SKIP_RECIPE").split(): + bb.note("Recipe has been whitelisted, skipping check") + return ([], [], []) + + cve_whitelist = d.getVar("CVE_CHECK_IGNORE").split() + + import sqlite3 + db_file = d.expand("file:${CVE_CHECK_DB_FILE}?mode=ro") + conn = sqlite3.connect(db_file, uri=True) + + # For each of the known product names (e.g. curl has CPEs using curl and libcurl)... + for product in products: + if ":" in product: + vendor, product = product.split(":", 1) + else: + vendor = "%" + + # Find all relevant CVE IDs. + for cverow in conn.execute("SELECT DISTINCT ID FROM PRODUCTS WHERE PRODUCT IS ? AND VENDOR LIKE ?", (product, vendor)): + cve = cverow[0] + + if cve in cve_whitelist: + bb.note("%s-%s has been whitelisted for %s" % (product, pv, cve)) + # TODO: this should be in the report as 'whitelisted' + patched_cves.add(cve) + continue + elif cve in patched_cves: + bb.note("%s has been patched" % (cve)) + continue + + vulnerable = False + for row in conn.execute("SELECT * FROM PRODUCTS WHERE ID IS ? AND PRODUCT IS ? AND VENDOR LIKE ?", (cve, product, vendor)): + (_, _, _, version_start, operator_start, version_end, operator_end) = row + #bb.debug(2, "Evaluating row " + str(row)) + + if (operator_start == '=' and pv == version_start) or version_start == '-': + vulnerable = True + else: + if operator_start: + try: + vulnerable_start = (operator_start == '>=' and Version(pv,suffix) >= Version(version_start,suffix)) + vulnerable_start |= (operator_start == '>' and Version(pv,suffix) > Version(version_start,suffix)) + except: + bb.warn("%s: Failed to compare %s %s %s for %s" % + (product, pv, operator_start, version_start, cve)) + vulnerable_start = False + else: + vulnerable_start = False + + if operator_end: + try: + vulnerable_end = (operator_end == '<=' and Version(pv,suffix) <= Version(version_end,suffix) ) + vulnerable_end |= (operator_end == '<' and Version(pv,suffix) < Version(version_end,suffix) ) + except: + bb.warn("%s: Failed to compare %s %s %s for %s" % + (product, pv, operator_end, version_end, cve)) + vulnerable_end = False + else: + vulnerable_end = False + + if operator_start and operator_end: + vulnerable = vulnerable_start and vulnerable_end + else: + vulnerable = vulnerable_start or vulnerable_end + + if vulnerable: + bb.note("%s-%s is vulnerable to %s" % (pn, real_pv, cve)) + cves_unpatched.append(cve) + break + + if not vulnerable: + bb.note("%s-%s is not vulnerable to %s" % (pn, real_pv, cve)) + # TODO: not patched but not vulnerable + patched_cves.add(cve) + + conn.close() + + return (list(cve_whitelist), list(patched_cves), cves_unpatched) + +def get_cve_info(d, cves): + """ + Get CVE information from the database. + """ + + import sqlite3 + + cve_data = {} + db_file = d.expand("file:${CVE_CHECK_DB_FILE}?mode=ro") + conn = sqlite3.connect(db_file, uri=True) + + for cve in cves: + for row in conn.execute("SELECT * FROM NVD WHERE ID IS ?", (cve,)): + cve_data[row[0]] = {} + cve_data[row[0]]["summary"] = row[1] + cve_data[row[0]]["scorev2"] = row[2] + cve_data[row[0]]["scorev3"] = row[3] + cve_data[row[0]]["modified"] = row[4] + cve_data[row[0]]["vector"] = row[5] + + conn.close() + return cve_data + +def cve_write_data(d, patched, unpatched, whitelisted, cve_data): + """ + Write CVE information in WORKDIR; and to CVE_CHECK_DIR, and + CVE manifest if enabled. + """ + + + cve_file = d.getVar("CVE_CHECK_LOG") + fdir_name = d.getVar("FILE_DIRNAME") + layer = fdir_name.split("/")[-3] + + include_layers = d.getVar("CVE_CHECK_LAYER_INCLUDELIST").split() + exclude_layers = d.getVar("CVE_CHECK_LAYER_EXCLUDELIST").split() + + if exclude_layers and layer in exclude_layers: + return + + if include_layers and layer not in include_layers: + return + + nvd_link = "https://nvd.nist.gov/vuln/detail/" + write_string = "" + unpatched_cves = [] + bb.utils.mkdirhier(os.path.dirname(cve_file)) + + for cve in sorted(cve_data): + is_patched = cve in patched + if is_patched and (d.getVar("CVE_CHECK_REPORT_PATCHED") != "1"): + continue + write_string += "LAYER: %s\n" % layer + write_string += "PACKAGE NAME: %s\n" % d.getVar("PN") + write_string += "PACKAGE VERSION: %s%s\n" % (d.getVar("EXTENDPE"), d.getVar("PV")) + write_string += "CVE: %s\n" % cve + if cve in whitelisted: + write_string += "CVE STATUS: Whitelisted\n" + elif is_patched: + write_string += "CVE STATUS: Patched\n" + else: + unpatched_cves.append(cve) + write_string += "CVE STATUS: Unpatched\n" + write_string += "CVE SUMMARY: %s\n" % cve_data[cve]["summary"] + write_string += "CVSS v2 BASE SCORE: %s\n" % cve_data[cve]["scorev2"] + write_string += "CVSS v3 BASE SCORE: %s\n" % cve_data[cve]["scorev3"] + write_string += "VECTOR: %s\n" % cve_data[cve]["vector"] + write_string += "MORE INFORMATION: %s%s\n\n" % (nvd_link, cve) + + if unpatched_cves: + bb.warn("Found unpatched CVE (%s), for more information check %s" % (" ".join(unpatched_cves),cve_file)) + + if write_string: + with open(cve_file, "w") as f: + bb.note("Writing file %s with CVE information" % cve_file) + f.write(write_string) + + if d.getVar("CVE_CHECK_COPY_FILES") == "1": + deploy_file = d.getVar("CVE_CHECK_RECIPE_FILE") + bb.utils.mkdirhier(os.path.dirname(deploy_file)) + with open(deploy_file, "w") as f: + f.write(write_string) + + if d.getVar("CVE_CHECK_CREATE_MANIFEST") == "1": + cvelogpath = d.getVar("CVE_CHECK_SUMMARY_DIR") + bb.utils.mkdirhier(cvelogpath) + + with open(d.getVar("CVE_CHECK_TMP_FILE"), "a") as f: + f.write("%s" % write_string) |