Turn CISA's KEV JSON into a bare-bones RSS feed

kev2rss.R

#!/usr/bin/Rscript

kev <- jsonlite::fromJSON("https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json")

vulns <- kev$vulnerabilities
vulns <- vulns[nrow(vulns):1,]

rss_body <- '
<rss version="2.0">
<channel>
	<title><![CDATA[CISA Known Exploited Vulnerabilities Catalog]]></title>
	<link>https://www.cisa.gov/known-exploited-vulnerabilities-catalog</link>
	<description><![CDATA[For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild: the Known Exploited Vulnerability (KEV) catalog. CISA strongly recommends all organizations review and monitor the KEV catalog and prioritize remediation of the listed vulnerabilities to reduce the likelihood of compromise by known threat actors.]]></description>
	%s
</channel>
</rss>
'

rss_item <- '
	<item>
		<title><![CDATA[%s]]></title>
		<link>%s</link>
		<guid>%s</guid>
		<description><![CDATA[%s]]></description>
	</item>
)'

urlencode <- function(.x) sapply(.x, URLencode, USE.NAMES = FALSE)

link_and_guid <- urlencode(file.path("https://nvd.nist.gov/vuln/detail", vulns$cveID))

sprintf(
  rss_body,
  paste0(
    sprintf(
      rss_item,
      sprintf("%s: [%s] %s", vulns$dateAdded, vulns$cveID, vulns$vulnerabilityName),
      link_and_guid,
      link_and_guid,
      vulns$shortDescription
    ),
    collapse = "\n"
  )
) -> out

cat(out, file="/var/sites/rud.is/cisa-kev.rss")