Anchore Policy Checks

Introduction

In this document, we describe the current anchore gates (and related triggers and parameters) that are supported within anchore policy.

Gate: dockerfile

Checks against the content of a dockerfile if provided, or a guessed dockerfile based on docker layer history if the dockerfile is not provided.

Note For further information on usage see Policy Gate: Dockerfile

Trigger Name	Description	Parameter	Description	Example
instruction	Triggers if any directives in the list are found to match the described condition in the dockerfile.	instruction	The Dockerfile instruction to check.	from
instruction	Triggers if any directives in the list are found to match the described condition in the dockerfile.	check	The type of check to perform.	=
instruction	Triggers if any directives in the list are found to match the described condition in the dockerfile.	value	The value to check the dockerfile instruction against.	scratch
instruction	Triggers if any directives in the list are found to match the described condition in the dockerfile.	actual_dockerfile_only	Only evaluate against a user-provided dockerfile, skip evaluation on inferred/guessed dockerfiles. Default is False.	true
effective_user	Checks if the effective user matches the provided user names, either as a allowlist or blocklist depending on the type parameter setting.	users	User names to check against as the effective user (last user entry) in the images history.	root,docker
effective_user	Checks if the effective user matches the provided user names, either as a allowlist or blocklist depending on the type parameter setting.	type	How to treat the provided user names.	denylist
exposed_ports	Evaluates the set of ports exposed. Allows configuring allowlist or blocklist behavior. If type=allowlist, then any ports found exposed that are not in the list will cause the trigger to fire. If type=denylist, then any ports exposed that are in the list will cause the trigger to fire.	ports	List of port numbers.	80,8080,8088
exposed_ports	Evaluates the set of ports exposed. Allows configuring allowlist or blocklist behavior. If type=allowlist, then any ports found exposed that are not in the list will cause the trigger to fire. If type=denylist, then any ports exposed that are in the list will cause the trigger to fire.	type	Whether to use port list as a allowlist or denylist.	denylist
exposed_ports	Evaluates the set of ports exposed. Allows configuring allowlist or blocklist behavior. If type=allowlist, then any ports found exposed that are not in the list will cause the trigger to fire. If type=denylist, then any ports exposed that are in the list will cause the trigger to fire.	actual_dockerfile_only	Only evaluate against a user-provided dockerfile, skip evaluation on inferred/guessed dockerfiles. Default is False.	true
no_dockerfile_provided	Triggers if anchore analysis was performed without supplying the actual image Dockerfile.

Gate: files

Checks against files in the analyzed image including file content, file names, and filesystem attributes.

Trigger Name	Description	Parameter	Description	Example
content_regex_match	Triggers for each file where the content search analyzer has found a match using configured regexes in the analyzer_config.yaml “content_search” section. If the parameter is set, the trigger will only fire for files that matched the named regex. Refer to your analyzer_config.yaml for the regex values.	regex_name	Regex string that also appears in the FILECHECK_CONTENTMATCH analyzer parameter in analyzer configuration, to limit the check to. If set, will only fire trigger when the specific named regex was found in a file.	.password.
name_match	Triggers if a file exists in the container that has a filename that matches the provided regex. This does have a performance impact on policy evaluation.	regex	Regex to apply to file names for match.	.*.pem
attribute_match	Triggers if a filename exists in the container that has attributes that match those which are provided . This check has a performance impact on policy evaluation.	filename	Filename to check against provided checksum.	/etc/passwd
attribute_match	Triggers if a filename exists in the container that has attributes that match those which are provided . This check has a performance impact on policy evaluation.	checksum_algorithm	Checksum algorithm	sha256
attribute_match	Triggers if a filename exists in the container that has attributes that match those which are provided . This check has a performance impact on policy evaluation.	checksum	Checksum of file.	832cd0f75b227d13aac82b1f70b7f90191a4186c151f9db50851d209c45ede11
attribute_match	Triggers if a filename exists in the container that has attributes that match those which are provided . This check has a performance impact on policy evaluation.	checksum_match	Checksum operation to perform.	equals
attribute_match	Triggers if a filename exists in the container that has attributes that match those which are provided . This check has a performance impact on policy evaluation.	mode	File mode of file.	00644
attribute_match	Triggers if a filename exists in the container that has attributes that match those which are provided . This check has a performance impact on policy evaluation.	mode_op	File mode operation to perform.	equals
attribute_match	Triggers if a filename exists in the container that has attributes that match those which are provided . This check has a performance impact on policy evaluation.	skip_missing	If set to true, do not fire this trigger if the file is not present. If set to false, fire this trigger ignoring the other parameter settings.	true
suid_or_guid_set	Fires for each file found to have suid or sgid bit set.

Gate: passwd_file

Content checks for /etc/passwd for things like usernames, group ids, shells, or full entries.

Trigger Name	Description	Parameter	Description	Example
content_not_available	Triggers if the /etc/passwd file is not present/stored in the evaluated image.
denylist_usernames	Triggers if specified username is found in the /etc/passwd file	user_names	List of usernames that will cause the trigger to fire if found in /etc/passwd.	daemon,ftp
denylist_userids	Triggers if specified user id is found in the /etc/passwd file	user_ids	List of userids (numeric) that will cause the trigger to fire if found in /etc/passwd.	0,1
denylist_groupids	Triggers if specified group id is found in the /etc/passwd file	group_ids	List of groupids (numeric) that will cause the trigger ot fire if found in /etc/passwd.	999,20
denylist_shells	Triggers if specified login shell for any user is found in the /etc/passwd file	shells	List of shell commands to denylist.	/bin/bash,/bin/zsh
denylist_full_entry	Triggers if entire specified passwd entry is found in the /etc/passwd file.	entry	Full entry to match in /etc/passwd.	ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin

Gate: packages

Distro package checks

Trigger Name	Description	Parameter	Description	Example
required_package	Triggers if the specified package and optionally a specific version is not found in the image.	name	Name of package that must be found installed in image.	libssl
required_package	Triggers if the specified package and optionally a specific version is not found in the image.	version	Optional version of package for exact version match.	1.10.3rc3
required_package	Triggers if the specified package and optionally a specific version is not found in the image.	version_match_type	The type of comparison to use for version if a version is provided.	exact
verify	Check package integrity against package db in the image. Triggers for changes or removal or content in all or the selected “dirs” parameter if provided, and can filter type of check with the “check_only” parameter.	only_packages	List of package names to limit verification.	libssl,openssl
verify	Check package integrity against package db in the image. Triggers for changes or removal or content in all or the selected “dirs” parameter if provided, and can filter type of check with the “check_only” parameter.	only_directories	List of directories to limit checks so as to avoid checks on all dir.	/usr,/var/lib
verify	Check package integrity against package db in the image. Triggers for changes or removal or content in all or the selected “dirs” parameter if provided, and can filter type of check with the “check_only” parameter.	check	Check to perform instead of all.	changed
denylist	Triggers if the evaluated image has a package installed that matches the named package optionally with a specific version as well.	name	Package name to denylist.	openssh-server
denylist	Triggers if the evaluated image has a package installed that matches the named package optionally with a specific version as well.	version	Specific version of package to denylist.	1.0.1
metadata	Triggers on a package type comparison.	type	The type of package.	rpm
metadata	Triggers on a package name comparison.	name	The name of the package. Wildcards are supported.	*ssl
metadata	Triggers on a package version comparison.	version	The version of the package. Wildcards are supported.	*fips

Gate: vulnerabilities

CVE/Vulnerability checks.

Trigger Name	Description	Parameter	Description	Example
package	Triggers if a found vulnerability in an image meets the comparison criteria.	package_type	Only trigger for specific package type.	all
package	Triggers if a found vulnerability in an image meets the comparison criteria.	severity_comparison	The type of comparison to perform for severity evaluation.	>
package	Triggers if a found vulnerability in an image meets the comparison criteria.	severity	Severity to compare against.	high
package	Triggers if a found vulnerability in an image meets the comparison criteria.	cvss_v3_base_score_comparison	The type of comparison to perform for CVSS v3 base score evaluation.	>
package	Triggers if a found vulnerability in an image meets the comparison criteria.	cvss_v3_base_score	CVSS v3 base score to compare against.	None
package	Triggers if a found vulnerability in an image meets the comparison criteria.	cvss_v3_exploitability_score_comparison	The type of comparison to perform for CVSS v3 exploitability sub score evaluation.	>
package	Triggers if a found vulnerability in an image meets the comparison criteria.	cvss_v3_exploitability_score	CVSS v3 exploitability sub score to compare against.	None
package	Triggers if a found vulnerability in an image meets the comparison criteria.	cvss_v3_impact_score_comparison	The type of comparison to perform for CVSS v3 impact sub score evaluation.	>
package	Triggers if a found vulnerability in an image meets the comparison criteria.	cvss_v3_impact_score	CVSS v3 impact sub score to compare against.	None
package	Triggers if a found vulnerability in an image meets the comparison criteria.	fix_available	If present, the fix availability for the vulnerability record must match the value of this parameter.	true
package	Triggers if a found vulnerability in an image meets the comparison criteria.	vendor_only	If True, an available fix for this CVE must not be explicitly marked as wont be addressed by the vendor	true
package	Triggers if a found vulnerability in an image meets the comparison criteria.	max_days_since_creation	If provided, this CVE must be older than the days provided to trigger.	7
package	Triggers if a found vulnerability in an image meets the comparison criteria.	max_days_since_fix	If provided (only evaluated when fix_available option is also set to true), the fix first observed time must be older than days provided, to trigger.	30
package	Triggers if a found vulnerability in an image meets the comparison criteria.	vendor_cvss_v3_base_score_comparison	The type of comparison to perform for vendor specified CVSS v3 base score evaluation.	>
package	Triggers if a found vulnerability in an image meets the comparison criteria.	vendor_cvss_v3_base_score	Vendor CVSS v3 base score to compare against.	None
package	Triggers if a found vulnerability in an image meets the comparison criteria.	vendor_cvss_v3_exploitability_score_comparison	The type of comparison to perform for vendor specified CVSS v3 exploitability sub score evaluation.	>
package	Triggers if a found vulnerability in an image meets the comparison criteria.	vendor_cvss_v3_exploitability_score	Vendor CVSS v3 exploitability sub score to compare against.	None
package	Triggers if a found vulnerability in an image meets the comparison criteria.	vendor_cvss_v3_impact_score_comparison	The type of comparison to perform for vendor specified CVSS v3 impact sub score evaluation.	>
package	Triggers if a found vulnerability in an image meets the comparison criteria.	vendor_cvss_v3_impact_score	Vendor CVSS v3 impact sub score to compare against.	None
package	Triggers if a found vulnerability in an image meets the comparison criteria.	package_path_exclude	The regex to evaluate against the package path to exclude vulnerabilities	.test.jar
package	Triggers if a found vulnerability in an image meets the comparison criteria.	inherited_from_base	If true, only show vulns inherited from the base, if false than only show vulns not inherited from the base. Don’t specify to include vulns from the base image and the current image.	True
denylist	Triggers if any of a list of specified vulnerabilities has been detected in the image.	vulnerability_ids	List of vulnerability IDs, will cause the trigger to fire if any are detected.	CVE-2019-1234
denylist	Triggers if any of a list of specified vulnerabilities has been detected in the image.	vendor_only	If set to True, discard matches against this vulnerability if vendor has marked as will not fix in the vulnerability record.	True
stale_feed_data	Triggers if the CVE data is older than the window specified by the parameter MAXAGE (unit is number of days).	max_days_since_sync	Fire the trigger if the last sync was more than this number of days ago.	10
vulnerability_data_unavailable	Triggers if vulnerability data is unavailable for the image’s distro packages such as rpms or dpkg. Non-OS packages like npms and java are not considered in this evaluation

Gate: licenses

License checks against found software licenses in the container image

Trigger Name	Description	Parameter	Description	Example
denylist_exact_match	Triggers if the evaluated image has a package installed with software distributed under the specified (exact match) license(s).	licenses	List of license names to denylist exactly.	GPLv2+,GPL-3+,BSD-2-clause
denylist_exact_match	Triggers if the evaluated image has a package installed with software distributed under the specified (exact match) license(s).	package_type	Only trigger for specific package type.	all
denylist_partial_match	triggers if the evaluated image has a package installed with software distributed under the specified (substring match) license(s)	licenses	List of strings to do substring match for denylist.	LGPL,BSD
denylist_partial_match	triggers if the evaluated image has a package installed with software distributed under the specified (substring match) license(s)	package_type	Only trigger for specific package type.	all

Gate: ruby_gems

Ruby Gem Checks

Trigger Name	Description	Parameter	Description	Example
newer_version_found_in_feed	Triggers if an installed GEM is not the latest version according to GEM data feed.
not_found_in_feed	Triggers if an installed GEM is not in the official GEM database, according to GEM data feed.
version_not_found_in_feed	Triggers if an installed GEM version is not listed in the official GEM feed as a valid version.
denylist	Triggers if the evaluated image has a GEM package installed that matches the specified name and version.	name	Gem name to denylist.	time_diff
denylist	Triggers if the evaluated image has a GEM package installed that matches the specified name and version.	version	Optional version to denylist specifically.	0.2.9
feed_data_unavailable	Triggers if anchore does not have access to the GEM data feed.

Gate: npms

NPM Checks

Trigger Name	Description	Parameter	Description	Example
newer_version_in_feed	Triggers if an installed NPM is not the latest version according to NPM data feed.
unknown_in_feeds	Triggers if an installed NPM is not in the official NPM database, according to NPM data feed.
version_not_in_feeds	Triggers if an installed NPM version is not listed in the official NPM feed as a valid version.
denylisted_name_version	Triggers if the evaluated image has an NPM package installed that matches the name and optionally a version specified in the parameters.	name	Npm package name to denylist.	time_diff
denylisted_name_version	Triggers if the evaluated image has an NPM package installed that matches the name and optionally a version specified in the parameters.	version	Npm package version to denylist specifically.	0.2.9
feed_data_unavailable	Triggers if the system does not have access to the NPM data feed.

Gate: secret_scans

Checks for secrets and content found in the image using configured regexes found in the “secret_search” section of analyzer_config.yaml.

Trigger Name	Description	Parameter	Description	Example
content_regex_checks	Triggers if the secret content search analyzer has found any matches with the configured and named regexes. Checks can be configured to trigger if a match is found or is not found (selected using match_type parameter). Matches are filtered by the content_regex_name and filename_regex if they are set. The content_regex_name shoud be a value from the “secret_search” section of the analyzer_config.yaml.	content_regex_name	Name of content regexps configured in the analyzer that match if found in the image, instead of matching all. Names available by default are: [‘AWS_ACCESS_KEY’, ‘AWS_SECRET_KEY’, ‘PRIV_KEY’, ‘DOCKER_AUTH’, ‘API_KEY’].	AWS_ACCESS_KEY
content_regex_checks	Triggers if the secret content search analyzer has found any matches with the configured and named regexes. Checks can be configured to trigger if a match is found or is not found (selected using match_type parameter). Matches are filtered by the content_regex_name and filename_regex if they are set. The content_regex_name shoud be a value from the “secret_search” section of the analyzer_config.yaml.	filename_regex	Regexp to filter the content matched files by.	/etc/.*
content_regex_checks	Triggers if the secret content search analyzer has found any matches with the configured and named regexes. Checks can be configured to trigger if a match is found or is not found (selected using match_type parameter). Matches are filtered by the content_regex_name and filename_regex if they are set. The content_regex_name shoud be a value from the “secret_search” section of the analyzer_config.yaml.	match_type	Set to define the type of match - trigger if match is found (default) or not found.	found

Gate: metadata

Checks against image metadata, such as size, OS, distro, architecture, etc.

Trigger Name	Description	Parameter	Description	Example
attribute	Triggers if a named image metadata value matches the given condition.	attribute	Attribute name to be checked.	size
attribute	Triggers if a named image metadata value matches the given condition.	check	The operation to perform the evaluation.	>
attribute	Triggers if a named image metadata value matches the given condition.	value	Value used in comparison.	1073741824

Gate: always

Triggers that fire unconditionally if present in policy, useful for things like testing and deny-listing.

Trigger Name	Description	Parameter	Description	Example
always	Fires if present in a policy being evaluated. Useful for things like deny-listing images or testing mappings and allowlists by using this trigger in combination with policy mapping rules.

Gate: retrieved_files

Checks against content and/or presence of files retrieved at analysis time from an image

Trigger Name	Description	Parameter	Description	Example
content_not_available	Triggers if the specified file is not present/stored in the evaluated image.	path	The path of the file to verify has been retrieved during analysis	/etc/httpd.conf
content_regex	Evaluation of regex on retrieved file content	path	The path of the file to verify has been retrieved during analysis	/etc/httpd.conf
content_regex	Evaluation of regex on retrieved file content	check	The type of check to perform with the regex	match
content_regex	Evaluation of regex on retrieved file content	regex	The regex to evaluate against the content of the file	.SSlEnabled.

Gate: Malware

Trigger	Description	Parameters
scans	Triggers if any malware scanner has found any matches in the image.
scan_not_run	Triggers if no scan was found for the image.

Gate: Tag Drift

Compares the SBOM from the evaluated image’s tag and the tag’s previous image, if found. Provides triggers to detect packages added, removed or modified.

Trigger Name	Description	Parameter	Description	Example
packages_added	Checks to see if any packages have been added.	package_type	Package type to filter for only specific types. If ommitted, then all types are evaluated.	apk
packages_removed	Checks to see if any packages have been removed.	package_type	Package type to filter for only specific types. If ommitted, then all types are evaluated.	apk
packages_modified	Checks to see if any packages have been modified.	package_type	Package type to filter for only specific types. If ommitted, then all types are evaluated.	apk

Gate: Image Source Drift

Triggers for evaluating diffs of an image’s source repo sbom and the built image. Operates on the diffs defined by ‘contains’ relationships where the image is the ‘source’ and the source revisions that are the ’target’ for the relationship.

Trigger Name	Description	Parameter	Description	Example
package_downgraded	Checks to see if any packages have a lower version in the built image than specified in the input source sboms	package_types	Types of package to filter by	java,npm
package_removed	Checks to see if any packages are not installed that were expected based on the image’s related input source sboms	package_types	Types of package to filter by	java,npm
no_related_sources	Checks to see if there are any source sboms related to the image. Findings indicate that the image does not have a source sbom to detect drift against

Gate: Ancestry

Checks the image ancestry against approved images.

Trigger Name	Description	Parameter	Description	Example
allowed_base_image_digest	Checks to see if base image is approved	base_digest	List of approved base image digests.	sha256:123abc
allowed_base_image_tag	Checks to see if base image is approved	base_tag	List of approved base image tags.	docker.io/debian:latest
no_ancestors_analyzed	Checks to see if the image has a known ancestor

Gate: Distro

Checks against the image distro metadata. This can be used to denylist versions of a distro, such as versions that are EOL.

Trigger Name	Description	Parameter	Description	Example
deny	Triggers if the image distro and version match the criteria	distro	Name of the distribution to match	debian
deny	Triggers if the image distro and version match the criteria	version	Version of distribution to compare against	9
deny	Triggers if the image distro and version match the criteria	check	The comparison to use in the evaluation	<

Next Steps

See how policy gates can be used in evaluation steps in Evaluating Images Against Policies

Last modified April 3, 2024