Fix stored XSS in HTML report via unescaped Location: header (#3090)

Backport of the 3.3dev fix to the 3.2 branch.

pr_url() and pr_boldurl() interpolated their argument directly into
<a href="$1">$1</a> without HTML escaping. The most notable caller
passes the raw HTTP Location: header from the scanned server, so a
malicious HTTPS target could inject arbitrary HTML/JS into an
operator's --htmlfile report. Route both the href attribute and the
link text through the existing html_reserved() escaper, matching the
pattern already used by every other pr_* HTML-output function.

CHANGELOG.md

@@ -1,6 +1,10 @@
 
 ## Change Log
 
+### Security fixes in 3.2.x
+
+* Security fix: HTML-escape URLs in the HTML report to prevent stored XSS from a server-controlled `Location:` header (#3090)
+
 ### Features implemented / improvements in 3.2
 
 * Rating (SSL Labs), as of 3.2.2 version 2009r

CREDITS.md

@@ -68,6 +68,9 @@ Full contribution, see git log.
 * Christian Dresen
    - Dockerfile
 
+* Eric Gu
+  - HTML report XSS fix (escape server-controlled URLs, #3090)
+
 * enxio
    - support for TN3270/telnet STARTTLS
 

testssl.sh

@@ -739,8 +739,8 @@ tmln_fixme() { tmln_warning "Fixme: $1"; }
 pr_fixme()   { pr_warning "Fixme: $1"; }
 prln_fixme() { prln_warning "Fixme: $1"; }
 
-pr_url()     { tm_out "$1"; html_out "<a href=\"$1\" style=\"color:black;text-decoration:none;\">$1</a>"; }
+pr_url()     { tm_out "$1"; html_out "<a href=\"$(html_reserved "$1")\" style=\"color:black;text-decoration:none;\">$(html_reserved "$1")</a>"; }
-pr_boldurl() { tm_bold "$1"; html_out "<a href=\"$1\" style=\"font-weight:bold;color:black;text-decoration:none;\">$1</a>"; }
+pr_boldurl() { tm_bold "$1"; html_out "<a href=\"$(html_reserved "$1")\" style=\"font-weight:bold;color:black;text-decoration:none;\">$(html_reserved "$1")</a>"; }
 
 ### color switcher (see e.g. https://linuxtidbits.wordpress.com/2008/08/11/output-color-on-bash-scripts/
 ###                          https://www.tldp.org/HOWTO/Bash-Prompt-HOWTO/x405.html