| # 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}/nvd.db" |
| |
| CVE_CHECK_LOG ?= "${T}/cve.log" |
| CVE_CHECK_TMP_FILE ?= "${TMPDIR}/cve_check" |
| |
| CVE_CHECK_DIR ??= "${DEPLOY_DIR}/cve" |
| CVE_CHECK_MANIFEST ?= "${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.cve" |
| CVE_CHECK_COPY_FILES ??= "1" |
| CVE_CHECK_CREATE_MANIFEST ??= "1" |
| |
| # Whitelist for packages (PN) |
| CVE_CHECK_PN_WHITELIST = "\ |
| glibc-locale \ |
| " |
| |
| # Whitelist for CVE and version of package |
| CVE_CHECK_CVE_WHITELIST = "{\ |
| 'CVE-2014-2524': ('6.3','5.2',), \ |
| }" |
| |
| python do_cve_check () { |
| """ |
| Check recipe for patched and unpatched CVEs |
| """ |
| |
| if os.path.exists(d.getVar("CVE_CHECK_TMP_FILE")): |
| patched_cves = get_patches_cves(d) |
| 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, cve_data) |
| else: |
| bb.note("Failed to update CVE database, skipping CVE check") |
| } |
| |
| addtask cve_check after do_unpack before do_build |
| do_cve_check[depends] = "cve-check-tool-native:do_populate_sysroot cve-check-tool-native:do_populate_cve_db" |
| 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 = os.path.join(d.getVar("CVE_CHECK_DIR"), d.getVar("PN")) |
| 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") |
| |
| 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 get_patches_cves(d): |
| """ |
| Get patches that solve CVEs using the "CVE: " tag. |
| """ |
| |
| import re |
| |
| pn = d.getVar("PN") |
| cve_match = re.compile("CVE:( CVE\-\d{4}\-\d+)+") |
| |
| # Matches last CVE-1234-211432 in the file name, also if written |
| # with small letters. Not supporting multiple CVE id's in a single |
| # file name. |
| cve_file_name_match = re.compile(".*([Cc][Vv][Ee]\-\d{4}\-\d+)") |
| |
| patched_cves = set() |
| bb.debug(2, "Looking for patches that solves CVEs for %s" % pn) |
| for url in src_patches(d): |
| patch_file = bb.fetch.decodeurl(url)[2] |
| |
| # Check patch file name for CVE ID |
| fname_match = cve_file_name_match.search(patch_file) |
| if fname_match: |
| cve = fname_match.group(1).upper() |
| patched_cves.add(cve) |
| bb.debug(2, "Found CVE %s from patch file name %s" % (cve, patch_file)) |
| |
| with open(patch_file, "r", encoding="utf-8") as f: |
| try: |
| patch_text = f.read() |
| except UnicodeDecodeError: |
| bb.debug(1, "Failed to read patch %s using UTF-8 encoding" |
| " trying with iso8859-1" % patch_file) |
| f.close() |
| with open(patch_file, "r", encoding="iso8859-1") as f: |
| patch_text = f.read() |
| |
| # Search for the "CVE: " line |
| match = cve_match.search(patch_text) |
| if match: |
| # Get only the CVEs without the "CVE: " tag |
| cves = patch_text[match.start()+5:match.end()] |
| for cve in cves.split(): |
| bb.debug(2, "Patch %s solves %s" % (patch_file, cve)) |
| patched_cves.add(cve) |
| elif not fname_match: |
| bb.debug(2, "Patch %s doesn't solve CVEs" % patch_file) |
| |
| return patched_cves |
| |
| def check_cves(d, patched_cves): |
| """ |
| Run cve-check-tool looking for patched and unpatched CVEs. |
| """ |
| |
| import ast, csv, tempfile, subprocess, io |
| |
| cves_patched = [] |
| cves_unpatched = [] |
| bpn = d.getVar("CVE_PRODUCT") |
| # If this has been unset then we're not scanning for CVEs here (for example, image recipes) |
| if not bpn: |
| return ([], []) |
| pv = d.getVar("CVE_VERSION").split("+git")[0] |
| cves = " ".join(patched_cves) |
| cve_db_dir = d.getVar("CVE_CHECK_DB_DIR") |
| cve_whitelist = ast.literal_eval(d.getVar("CVE_CHECK_CVE_WHITELIST")) |
| cve_cmd = "cve-check-tool" |
| cmd = [cve_cmd, "--no-html", "--csv", "--not-affected", "-t", "faux", "-d", cve_db_dir] |
| |
| # If the recipe has been whitlisted we return empty lists |
| if d.getVar("PN") in d.getVar("CVE_CHECK_PN_WHITELIST").split(): |
| bb.note("Recipe has been whitelisted, skipping check") |
| return ([], []) |
| |
| try: |
| # Write the faux CSV file to be used with cve-check-tool |
| fd, faux = tempfile.mkstemp(prefix="cve-faux-") |
| with os.fdopen(fd, "w") as f: |
| f.write("%s,%s,%s," % (bpn, pv, cves)) |
| cmd.append(faux) |
| |
| output = subprocess.check_output(cmd).decode("utf-8") |
| bb.debug(2, "Output of command %s:\n%s" % ("\n".join(cmd), output)) |
| except subprocess.CalledProcessError as e: |
| bb.warn("Couldn't check for CVEs: %s (output %s)" % (e, e.output)) |
| finally: |
| os.remove(faux) |
| |
| for row in csv.reader(io.StringIO(output)): |
| # Third row has the unpatched CVEs |
| if row[2]: |
| for cve in row[2].split(): |
| # Skip if the CVE has been whitlisted for the current version |
| if pv in cve_whitelist.get(cve,[]): |
| bb.note("%s-%s has been whitelisted for %s" % (bpn, pv, cve)) |
| else: |
| cves_unpatched.append(cve) |
| bb.debug(2, "%s-%s is not patched for %s" % (bpn, pv, cve)) |
| # Fourth row has patched CVEs |
| if row[3]: |
| for cve in row[3].split(): |
| cves_patched.append(cve) |
| bb.debug(2, "%s-%s is patched for %s" % (bpn, pv, cve)) |
| |
| return (cves_patched, cves_unpatched) |
| |
| def get_cve_info(d, cves): |
| """ |
| Get CVE information from the database used by cve-check-tool. |
| |
| Unfortunately the only way to get CVE info is set the output to |
| html (hard to parse) or query directly the database. |
| """ |
| |
| try: |
| import sqlite3 |
| except ImportError: |
| from pysqlite2 import dbapi2 as sqlite3 |
| |
| cve_data = {} |
| db_file = d.getVar("CVE_CHECK_DB_FILE") |
| placeholder = ",".join("?" * len(cves)) |
| query = "SELECT * FROM NVD WHERE id IN (%s)" % placeholder |
| conn = sqlite3.connect(db_file) |
| cur = conn.cursor() |
| for row in cur.execute(query, tuple(cves)): |
| cve_data[row[0]] = {} |
| cve_data[row[0]]["summary"] = row[1] |
| cve_data[row[0]]["score"] = row[2] |
| cve_data[row[0]]["modified"] = row[3] |
| cve_data[row[0]]["vector"] = row[4] |
| conn.close() |
| |
| return cve_data |
| |
| def cve_write_data(d, patched, unpatched, cve_data): |
| """ |
| Write CVE information in WORKDIR; and to CVE_CHECK_DIR, and |
| CVE manifest if enabled. |
| """ |
| |
| cve_file = d.getVar("CVE_CHECK_LOG") |
| nvd_link = "https://web.nvd.nist.gov/view/vuln/detail?vulnId=" |
| write_string = "" |
| unpatched_cves = [] |
| bb.utils.mkdirhier(os.path.dirname(cve_file)) |
| |
| for cve in sorted(cve_data): |
| write_string += "PACKAGE NAME: %s\n" % d.getVar("PN") |
| write_string += "PACKAGE VERSION: %s\n" % d.getVar("PV") |
| write_string += "CVE: %s\n" % cve |
| if cve in 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]["score"] |
| 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)) |
| |
| 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": |
| cve_dir = d.getVar("CVE_CHECK_DIR") |
| bb.utils.mkdirhier(cve_dir) |
| deploy_file = os.path.join(cve_dir, d.getVar("PN")) |
| with open(deploy_file, "w") as f: |
| f.write(write_string) |
| |
| if d.getVar("CVE_CHECK_CREATE_MANIFEST") == "1": |
| with open(d.getVar("CVE_CHECK_TMP_FILE"), "a") as f: |
| f.write("%s" % write_string) |