internal/frontend: vuln alias links always point to mitre entry

The alias reference links have been removed from the reports,
so we can no longer depend on them to determine when to link
to mitre or nist. Switched to the mitre link because an entry
will exist on mitre.org for all CVEs.

Change-Id: I3c0abbb0a7c8bc2c420dfc3741af92675d9b46ed
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/427535
Run-TryBot: Jamal Carvalho <jamal@golang.org>
Auto-Submit: Jamal Carvalho <jamal@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Julie Qiu <julieqiu@google.com>
diff --git a/internal/frontend/vulns.go b/internal/frontend/vulns.go
index 159b8cd..217d511 100644
--- a/internal/frontend/vulns.go
+++ b/internal/frontend/vulns.go
@@ -321,19 +321,12 @@
 
 // aliasLinks generates links to reference pages for vuln aliases.
 func aliasLinks(e *osv.Entry) []link {
-	var cveRef string
-	for _, ref := range e.References {
-		if strings.HasPrefix(ref.URL, nistAdvisoryUrlPrefix) || strings.HasPrefix(ref.URL, mitreAdvisoryUrlPrefix) {
-			cveRef = ref.URL
-			break
-		}
-	}
 	var links []link
 	for _, a := range e.Aliases {
 		prefix, _, _ := strings.Cut(a, "-")
 		switch prefix {
 		case "CVE":
-			links = append(links, link{Body: a, Href: cveRef})
+			links = append(links, link{Body: a, Href: mitreAdvisoryUrlPrefix + a})
 		case "GHSA":
 			links = append(links, link{Body: a, Href: githubAdvisoryUrlPrefix + a})
 		default:
diff --git a/internal/frontend/vulns_test.go b/internal/frontend/vulns_test.go
index ee91d62..a130ddb 100644
--- a/internal/frontend/vulns_test.go
+++ b/internal/frontend/vulns_test.go
@@ -166,14 +166,9 @@
 		want []link
 	}{
 		{
-			"reserved cve",
-			args{&osv.Entry{Aliases: []string{"CVE-0000-00000"}}},
-			[]link{{Body: "CVE-0000-00000"}},
-		},
-		{
-			"nist",
-			args{&osv.Entry{Aliases: []string{"CVE-0000-00000"}, References: []osv.Reference{{Type: "ADVISORY", URL: nistAdvisoryUrlPrefix + "CVE-0000-00000"}}}},
-			[]link{{Body: "CVE-0000-00000", Href: nistAdvisoryUrlPrefix + "CVE-0000-00000"}},
+			"mitre",
+			args{&osv.Entry{Aliases: []string{"CVE-0000-00000"}, References: []osv.Reference{{Type: "ADVISORY", URL: mitreAdvisoryUrlPrefix + "CVE-0000-00000"}}}},
+			[]link{{Body: "CVE-0000-00000", Href: mitreAdvisoryUrlPrefix + "CVE-0000-00000"}},
 		},
 		{
 			"github",