feat(vuln): enable --vex for all targets (aquasecurity#5992)

Signed-off-by: knqyf263 <knqyf263@gmail.com> Co-authored-by: DmitriyLewen <91113035+DmitriyLewen@users.noreply.github.com>
DmitriyLewen · Jan 25, 2024 · e2eb70e · e2eb70e
1 parent f9da021
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diff --git a/docs/docs/references/configuration/cli/trivy_filesystem.md b/docs/docs/references/configuration/cli/trivy_filesystem.md
@@ -87,6 +87,7 @@ trivy filesystem [flags] PATH
       --token-header string               specify a header name for token in client/server mode (default "Trivy-Token")
       --trace                             enable more verbose trace output for custom queries
       --username strings                  username. Comma-separated usernames allowed.
+      --vex string                        [EXPERIMENTAL] file path to VEX
       --vuln-type strings                 comma-separated list of vulnerability types (os,library) (default [os,library])
 ```
 

diff --git a/docs/docs/references/configuration/cli/trivy_image.md b/docs/docs/references/configuration/cli/trivy_image.md
@@ -106,6 +106,7 @@ trivy image [flags] IMAGE_NAME
       --token-header string               specify a header name for token in client/server mode (default "Trivy-Token")
       --trace                             enable more verbose trace output for custom queries
       --username strings                  username. Comma-separated usernames allowed.
+      --vex string                        [EXPERIMENTAL] file path to VEX
       --vuln-type strings                 comma-separated list of vulnerability types (os,library) (default [os,library])
 ```
 

diff --git a/docs/docs/references/configuration/cli/trivy_kubernetes.md b/docs/docs/references/configuration/cli/trivy_kubernetes.md
@@ -97,6 +97,7 @@ trivy kubernetes [flags] { cluster | all | specific resources like kubectl. eg:
       --tolerations strings               specify node-collector job tolerations (example: key1=value1:NoExecute,key2=value2:NoSchedule)
       --trace                             enable more verbose trace output for custom queries
       --username strings                  username. Comma-separated usernames allowed.
+      --vex string                        [EXPERIMENTAL] file path to VEX
       --vuln-type strings                 comma-separated list of vulnerability types (os,library) (default [os,library])
 ```
 

diff --git a/docs/docs/references/configuration/cli/trivy_repository.md b/docs/docs/references/configuration/cli/trivy_repository.md
@@ -87,6 +87,7 @@ trivy repository [flags] (REPO_PATH | REPO_URL)
       --token-header string               specify a header name for token in client/server mode (default "Trivy-Token")
       --trace                             enable more verbose trace output for custom queries
       --username strings                  username. Comma-separated usernames allowed.
+      --vex string                        [EXPERIMENTAL] file path to VEX
       --vuln-type strings                 comma-separated list of vulnerability types (os,library) (default [os,library])
 ```
 

diff --git a/docs/docs/references/configuration/cli/trivy_rootfs.md b/docs/docs/references/configuration/cli/trivy_rootfs.md
@@ -88,6 +88,7 @@ trivy rootfs [flags] ROOTDIR
       --token-header string               specify a header name for token in client/server mode (default "Trivy-Token")
       --trace                             enable more verbose trace output for custom queries
       --username strings                  username. Comma-separated usernames allowed.
+      --vex string                        [EXPERIMENTAL] file path to VEX
       --vuln-type strings                 comma-separated list of vulnerability types (os,library) (default [os,library])
 ```
 

diff --git a/docs/docs/references/configuration/cli/trivy_vm.md b/docs/docs/references/configuration/cli/trivy_vm.md
@@ -75,6 +75,7 @@ trivy vm [flags] VM_IMAGE
       --tf-exclude-downloaded-modules     exclude misconfigurations for downloaded terraform modules
       --token string                      for authentication in client/server mode
       --token-header string               specify a header name for token in client/server mode (default "Trivy-Token")
+      --vex string                        [EXPERIMENTAL] file path to VEX
       --vuln-type strings                 comma-separated list of vulnerability types (os,library) (default [os,library])
 ```
 

diff --git a/docs/docs/supply-chain/vex.md b/docs/docs/supply-chain/vex.md
@@ -4,7 +4,7 @@
     This feature might change without preserving backwards compatibility.
 
 Trivy supports filtering detected vulnerabilities using [the Vulnerability Exploitability Exchange (VEX)](https://www.ntia.gov/files/ntia/publications/vex_one-page_summary.pdf), a standardized format for sharing and exchanging information about vulnerabilities.
-By providing VEX alongside the Software Bill of Materials (SBOM) during scanning, it is possible to filter vulnerabilities based on their status.
+By providing VEX during scanning, it is possible to filter vulnerabilities based on their status.
 Currently, Trivy supports the following three formats:
 
 - [CycloneDX](https://cyclonedx.org/capabilities/vex/)
@@ -14,6 +14,15 @@ Currently, Trivy supports the following three formats:
 This is still an experimental implementation, with only minimal functionality added.
 
 ## CycloneDX
+|     Target      | Supported |
+|:---------------:|:---------:|
+| Container Image |           |
+|   Filesystem    |           |
+| Code Repository |           |
+|    VM Image     |           |
+|   Kubernetes    |           |
+|      SBOM       |     ✅     |
+
 There are [two VEX formats](https://cyclonedx.org/capabilities/vex/) for CycloneDX:
 
 - Independent BOM and VEX BOM
@@ -28,7 +37,7 @@ The following steps are required:
 2. Create a VEX based on the SBOM generated in step 1
 3. Provide the VEX when scanning the CycloneDX SBOM
 
-### Generating the SBOM
+### Generate the SBOM
 You can generate a CycloneDX SBOM with Trivy as follows:
 
 ```shell
@@ -117,23 +126,24 @@ Total: 1 (UNKNOWN: 0, LOW: 1, MEDIUM: 0, HIGH: 0, CRITICAL: 0)
 CVE-2020-8911 is no longer shown as it is filtered out according to the given CycloneDX VEX document.
 
 ## OpenVEX
+|     Target      | Supported |
+|:---------------:|:---------:|
+| Container Image |     ✅     |
+|   Filesystem    |     ✅     |
+| Code Repository |     ✅     |
+|    VM Image     |     ✅     |
+|   Kubernetes    |     ✅     |
+|      SBOM       |     ✅     |
+
 Trivy also supports [OpenVEX][openvex] that is designed to be minimal, compliant, interoperable, and embeddable.
-Since OpenVEX aims to be SBOM format agnostic, both CycloneDX and SPDX formats are available for use as input SBOMs in Trivy.
+OpenVEX can be used in all Trivy targets, unlike CycloneDX VEX.
 
 The following steps are required:
 
-1. Generate a SBOM (CycloneDX or SPDX)
-2. Create a VEX based on the SBOM generated in step 1
-3. Provide the VEX when scanning the SBOM
+1. Create a VEX document
+2. Provide the VEX when scanning your target
 
-### Generating the SBOM
-You can generate a CycloneDX or SPDX SBOM with Trivy as follows:
-
-```shell
-$ trivy image --format spdx-json --output debian11.spdx.json debian:11
-```
-
-### Create the VEX
+### Create the VEX document
 Please see also [the example](https://github.com/openvex/examples).
 In Trivy, [the Package URL (PURL)][purl] is used as the product identifier.
 
@@ -167,11 +177,11 @@ In the above example, PURLs, located in `packages.externalRefs.referenceLocator`
     `pkg:deb/debian/curl@7.50.3-1` in OpenVEX matches `pkg:deb/debian/curl@7.50.3-1?arch=i386`, 
     while `pkg:deb/debian/curl@7.50.3-1?arch=amd64` does not match `pkg:deb/debian/curl@7.50.3-1?arch=i386`.
 
-### Scan SBOM with VEX
-Provide the VEX when scanning the SBOM.
+### Scan with VEX
+Provide the VEX when scanning your target.
 
 ```
-$ trivy sbom debian11.spdx.json --vex debian11.openvex
+$ trivy image debian:11 --vex debian11.openvex
 ...
 2023-04-26T17:56:05.358+0300    INFO    Filtered out the detected vulnerability {"VEX format": "OpenVEX", "vulnerability-id": "CVE-2019-8457", "status": "not_affected", "justification": "vulnerable_code_not_in_execute_path"}
 
@@ -182,25 +192,25 @@ Total: 80 (UNKNOWN: 0, LOW: 58, MEDIUM: 6, HIGH: 16, CRITICAL: 0)
 
 CVE-2019-8457 is no longer shown as it is filtered out according to the given OpenVEX document.
 
-[openvex]: https://github.com/openvex/spec
-[purl]: https://github.com/package-url/purl-spec
 
 ## CSAF
+|     Target      | Supported |
+|:---------------:|:---------:|
+| Container Image |     ✅     |
+|   Filesystem    |     ✅     |
+| Code Repository |     ✅     |
+|    VM Image     |     ✅     |
+|   Kubernetes    |     ✅     |
+|      SBOM       |     ✅     |
+
 Trivy also supports [CSAF][csaf] format for VEX.
 Since CSAF aims to be SBOM format agnostic, both CycloneDX and SPDX formats are available for use as input SBOMs in Trivy.
 
 The following steps are required:
 
-1. Generate a SBOM (CycloneDX or SPDX)
-2. Create a CSAF document based on the SBOM generated in step 1
-3. Provide the CSAF document when scanning the SBOM
-
-### Generating the SBOM
-You can generate a CycloneDX or SPDX SBOM with Trivy as follows:
+1. Create a CSAF document
+2. Provide the CSAF when scanning your target
 
-```shell
-$ trivy image --format spdx-json --output debian11.spdx.json debian:11
-```
 
 ### Create the CSAF document
 Create a CSAF document in JSON format as follows:
@@ -303,11 +313,11 @@ $ cat <<EOF > debian11.vex.csaf
 EOF
 ```
 
-### Scan SBOM with CSAF document
-Provide the CSAF document when scanning the SBOM.
+### Scan with CSAF VEX
+Provide the CSAF document when scanning your target.
 
 ```console
-$ trivy sbom debian11.spdx.json --vex debian11.vex.csaf
+$ trivy image debian:11 --vex debian11.vex.csaf
 ...
 2024-01-02T10:28:26.704+0100	INFO	Filtered out the detected vulnerability	{"VEX format": "CSAF", "vulnerability-id": "CVE-2019-8457", "status": "not_affected"}
 
@@ -318,4 +328,51 @@ Total: 80 (UNKNOWN: 0, LOW: 58, MEDIUM: 6, HIGH: 16, CRITICAL: 0)
 
 CVE-2019-8457 is no longer shown as it is filtered out according to the given CSAF document.
 
+## Appendix
+### PURL matching
+In the context of VEX, Package URLs (PURLs) are utilized to identify specific software packages and their versions.
+The PURL matching specification outlines how PURLs are interpreted for vulnerability exception processing, ensuring precise identification and broad coverage of software packages.
+
+!!! note
+    The following PURL matching rules are not formally defined within the current official PURL specification.
+    Instead, they represent [a community consensus][purl-matching] on how to interpret PURLs.
+
+Below are the key aspects of the PURL matching rules:
+
+#### Matching Without Version
+A PURL without a specified version (e.g., `pkg:maven/com.google.guava/guava`) matches all versions of that package.
+This rule simplifies the application of vulnerability exceptions to all versions of a package.
+
+**Example**: `pkg:maven/com.google.guava/guava` matches:
+
+- All versions of `guava`, such as `com.google.guava:guava:24.1.1`, `com.google.guava:guava:30.0`.
+
+#### Matching Without Qualifiers
+A PURL without any qualifiers (e.g., `pkg:maven/com.google.guava/guava@24.1.1`) matches any variation of that package, irrespective of qualifiers.
+This approach ensures broad matching capabilities, covering all architectural or platform-specific variations of a package version.
+
+**Example**: `pkg:maven/com.google.guava/guava@24.1.1` matches:
+
+- `pkg:maven/com.google.guava/guava@24.1.1?classifier=x86`
+- `pkg:maven/com.google.guava/guava@24.1.1?type=pom`
+
+#### Matching With Specific Qualifiers
+A PURL that includes specific qualifiers (e.g., `pkg:maven/com.google.guava/guava@24.1.1?classifier=x86`) matches only those package versions that include the same qualifiers.
+
+**Example**: `pkg:maven/com.google.guava/guava@24.1.1?classifier=x86` matches:
+
+- `pkg:maven/com.google.guava/guava@24.1.1?classifier=x86&type=dll`
+    - Extra qualifiers (e.g., `type=dll`) are ignored.
+
+does not match:
+
+- `pkg:maven/com.google.guava/guava@24.1.1`
+    - `classifier=x86` is missing.
+- `pkg:maven/com.google.guava/guava@24.1.1?classifier=sources`
+    - `classifier` must have the same value.
+
+
 [csaf]: https://oasis-open.github.io/csaf-documentation/specification.html
+[openvex]: https://github.com/openvex/spec
+[purl]: https://github.com/package-url/purl-spec
+[purl-matching]: https://github.com/openvex/spec/issues/27
diff --git a/pkg/flag/sbom_flags.go b/pkg/flag/sbom_flags.go
@@ -21,29 +21,20 @@ var (
 		Usage:      "deprecated",
 		Deprecated: true,
 	}
-	VEXFlag = Flag{
-		Name:       "vex",
-		ConfigName: "sbom.vex",
-		Default:    "",
-		Usage:      "[EXPERIMENTAL] file path to VEX",
-	}
 )
 
 type SBOMFlagGroup struct {
 	ArtifactType *Flag // deprecated
 	SBOMFormat   *Flag // deprecated
-	VEXPath      *Flag
 }
 
 type SBOMOptions struct {
-	VEXPath string
 }
 
 func NewSBOMFlagGroup() *SBOMFlagGroup {
 	return &SBOMFlagGroup{
 		ArtifactType: &ArtifactTypeFlag,
 		SBOMFormat:   &SBOMFormatFlag,
-		VEXPath:      &VEXFlag,
 	}
 }
 
@@ -55,7 +46,6 @@ func (f *SBOMFlagGroup) Flags() []*Flag {
 	return []*Flag{
 		f.ArtifactType,
 		f.SBOMFormat,
-		f.VEXPath,
 	}
 }
 
@@ -69,7 +59,5 @@ func (f *SBOMFlagGroup) ToOptions() (SBOMOptions, error) {
 		return SBOMOptions{}, xerrors.New("'--artifact-type' and '--sbom-format' are no longer available")
 	}
 
-	return SBOMOptions{
-		VEXPath: getString(f.VEXPath),
-	}, nil
+	return SBOMOptions{}, nil
 }
diff --git a/pkg/flag/vulnerability_flags.go b/pkg/flag/vulnerability_flags.go
@@ -35,24 +35,33 @@ var (
 		Values:     dbTypes.Statuses,
 		Usage:      "comma-separated list of vulnerability status to ignore",
 	}
+	VEXFlag = Flag{
+		Name:       "vex",
+		ConfigName: "vulnerability.vex",
+		Default:    "",
+		Usage:      "[EXPERIMENTAL] file path to VEX",
+	}
 )
 
 type VulnerabilityFlagGroup struct {
 	VulnType      *Flag
 	IgnoreUnfixed *Flag
 	IgnoreStatus  *Flag
+	VEXPath       *Flag
 }
 
 type VulnerabilityOptions struct {
 	VulnType       []string
 	IgnoreStatuses []dbTypes.Status
+	VEXPath        string
 }
 
 func NewVulnerabilityFlagGroup() *VulnerabilityFlagGroup {
 	return &VulnerabilityFlagGroup{
 		VulnType:      &VulnTypeFlag,
 		IgnoreUnfixed: &IgnoreUnfixedFlag,
 		IgnoreStatus:  &IgnoreStatusFlag,
+		VEXPath:       &VEXFlag,
 	}
 }
 
@@ -65,6 +74,7 @@ func (f *VulnerabilityFlagGroup) Flags() []*Flag {
 		f.VulnType,
 		f.IgnoreUnfixed,
 		f.IgnoreStatus,
+		f.VEXPath,
 	}
 }
 
@@ -95,5 +105,6 @@ func (f *VulnerabilityFlagGroup) ToOptions() VulnerabilityOptions {
 	return VulnerabilityOptions{
 		VulnType:       getStringSlice(f.VulnType),
 		IgnoreStatuses: ignoreStatuses,
+		VEXPath:        getString(f.VEXPath),
 	}
 }