According to the version in its SIP banner, the version of Asterisk running on the remote host is potentially affected by a double-free error related to the ‘res_http_websocket’ module and handling of zero-length payloads that could allow denial of service attacks.
Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(80036);
script_version("1.11");
script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/11");
script_cve_id("CVE-2014-9374");
script_bugtraq_id(71607);
script_name(english:"Asterisk 'res_http_websocket' Double-Free DoS (AST-2014-019)");
script_set_attribute(attribute:"synopsis", value:
"A telephony application running on the remote host is affected by a
denial of service vulnerability.");
script_set_attribute(attribute:"description", value:
"According to the version in its SIP banner, the version of Asterisk
running on the remote host is potentially affected by a double-free
error related to the 'res_http_websocket' module and handling of
zero-length payloads that could allow denial of service attacks.
Note that Nessus has not tested for these issues but has instead
relied only on the application's self-reported version number.");
script_set_attribute(attribute:"see_also", value:"http://downloads.asterisk.org/pub/security/AST-2014-019.html");
script_set_attribute(attribute:"see_also", value:"https://issues.asterisk.org/jira/browse/ASTERISK-24472");
script_set_attribute(attribute:"solution", value:
"Upgrade to Asterisk 11.14.2 / 12.7.2 / 13.0.2 / 11.6-cert9 or apply
the appropriate patch listed in the Asterisk advisory.
Alternatively, as a workaround, disable the built-in HTTP server.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2014-9374");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"exploit_available", value:"false");
script_set_attribute(attribute:"vuln_publication_date", value:"2014/12/10");
script_set_attribute(attribute:"patch_publication_date", value:"2014/12/10");
script_set_attribute(attribute:"plugin_publication_date", value:"2014/12/15");
script_set_attribute(attribute:"potential_vulnerability", value:"true");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_set_attribute(attribute:"cpe", value:"cpe:/a:digium:asterisk");
script_set_attribute(attribute:"thorough_tests", value:"true");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"Misc.");
script_copyright(english:"This script is Copyright (C) 2014-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("asterisk_detection.nasl");
script_require_keys("asterisk/sip_detected", "Settings/ParanoidReport");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
get_kb_item_or_exit("asterisk/sip_detected");
asterisk_kbs = get_kb_list_or_exit("sip/asterisk/*/version");
if (report_paranoia < 2) audit(AUDIT_PARANOID);
is_vuln = FALSE;
not_vuln_installs = make_list();
errors = make_list();
foreach kb_name (keys(asterisk_kbs))
{
vulnerable = 0;
matches = eregmatch(pattern:"/(udp|tcp)/([0-9]+)/version", string:kb_name);
if (isnull(matches))
{
errors = make_list(errors, "Unexpected error parsing port number from '"+kb_name+"'.");
continue;
}
proto = matches[1];
port = matches[2];
version = asterisk_kbs[kb_name];
if (version == 'unknown')
{
errors = make_list(errors, "Unable to obtain version of install on " + proto + "/" + port + ".");
continue;
}
banner = get_kb_item("sip/asterisk/" + proto + "/" + port + "/source");
if (!banner)
{
# We have version but banner is missing;
# log error and use in version-check though.
errors = make_list(errors, "KB item 'sip/asterisk/" + proto + "/" + port + "/source' is missing.");
banner = 'unknown';
}
# Open Source 11.x < 11.14.2
if (version =~ "^11([^0-9]|$)" && "cert" >!< tolower(version))
{
fixed = "11.14.2";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
# Open Source 12.x < 12.7.2
else if (version =~ "^12([^0-9]|$)" && "cert" >!< tolower(version))
{
fixed = "12.7.2";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
# Open Source 13.x < 13.0.2
else if (version =~ "^13([^0-9]|$)" && "cert" >!< tolower(version))
{
fixed = "13.0.2";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
# Asterisk Certified 11.6-certx < 11.6-cert9
else if (version =~ "^11\.6([^0-9])" && "cert" >< tolower(version))
{
fixed = "11.6-cert9";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
if (vulnerable < 0)
{
is_vuln = TRUE;
if (report_verbosity > 0)
{
report =
'\n Version source : ' + banner +
'\n Installed version : ' + version +
'\n Fixed version : ' + fixed +
'\n';
security_warning(port:port, proto:proto, extra:report);
}
else security_warning(port:port, proto:proto);
}
else not_vuln_installs = make_list(not_vuln_installs, version + " on port " + proto + "/" + port);
}
if (max_index(errors))
{
if (max_index(errors) == 1) errmsg = errors[0];
else errmsg = 'Errors were encountered verifying installs : \n ' + join(errors, sep:'\n ');
exit(1, errmsg);
}
else
{
installs = max_index(not_vuln_installs);
if (installs == 0)
{
if (is_vuln) exit(0);
else audit(AUDIT_NOT_INST, "Asterisk");
}
else audit(AUDIT_INST_VER_NOT_VULN, "Asterisk", not_vuln_installs);
}