CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:S/C:P/I:P/A:P
EPSS
Percentile
91.3%
Using a specially crafted caller ID string, an authenticated user placing an outgoing call through the remote Asterisk server can cause a buffer overflow leading to an application crash or execution of arbitrary code.
Successful exploitation may require that the SIP channel driver is configured with the ‘pedantic’ option enabled.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(51644);
script_version("1.18");
script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/11");
script_cve_id("CVE-2011-0495");
script_bugtraq_id(45839);
script_xref(name:"SECUNIA", value:"42935");
script_name(english:"Asterisk main/utils.c ast_uri_encode() CallerID Information Overflow (AST-2011-001)");
script_set_attribute(attribute:"synopsis", value:
"A telephony application running on the remote host is affected by a
buffer overflow vulnerability.");
script_set_attribute(attribute:"description", value:
"Using a specially crafted caller ID string, an authenticated user
placing an outgoing call through the remote Asterisk server can cause
a buffer overflow leading to an application crash or execution of
arbitrary code.
Successful exploitation may require that the SIP channel driver is
configured with the 'pedantic' option enabled.");
script_set_attribute(attribute:"see_also", value:"http://downloads.asterisk.org/pub/security/AST-2011-001.html");
script_set_attribute(attribute:"solution", value:
"Upgrade to Asterisk 1.4.38.1 / 1.4.39.1 / 1.6.1.21 / 1.6.2.15.1 /
1.6.2.16.1 / 1.8.1.2 / 1.8.2.2, Asterisk Business Edition C.3.6.2 or
later.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
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:"2011/01/11");
script_set_attribute(attribute:"patch_publication_date", value:"2011/01/18");
script_set_attribute(attribute:"plugin_publication_date", value:"2011/01/21");
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:"Gain a shell remotely");
script_copyright(english:"This script is Copyright (C) 2011-2022 Tenable Network Security, Inc.");
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");
# see if we were able to get version info from the Asterisk SIP services
asterisk_kbs = get_kb_list("sip/asterisk/*/version");
if (isnull(asterisk_kbs)) exit(1, "Could not obtain any version information from the Asterisk SIP instance(s).");
# Prevent potential false positives.
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: "+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';
}
if (version =~ '^1\\.2([^0-9]|$)')
{
# No longer supported by vendor.
fixed = "The 1.2 branch is no longer supported.";
vulnerable = -1;
}
else if (version =~ '^1\\.4([^0-9]|$)')
{
if (version =~ '^1\\.4\\.38([^0-9]|$)')
{
fixed = "1.4.38.1";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
else if (version =~ '^1\\.4\\.39([^0-9]|$)')
{
fixed = "1.4.39.1";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
else
{
# Recommend lowest patched version in the 1.4 branch.
fixed = "1.4.38.1";
vulnerable = ver_compare(ver:version, fix:"1.4.40", app:"asterisk");
}
}
else if (version =~ '^1\\.6([^0-9]|$)')
{
if (version =~ '^1\\.6\\.1([^0-9]|$)')
{
fixed = "1.6.1.21";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
else if (version =~ '^1\\.6\\.2([^0-9]|$)')
{
if (version =~ '^1\\.6\\.2\\.15([^0-9]|$)')
{
fixed = "1.6.2.15.1";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
else if (version =~ '^1\\.6\\.2\\.16([^0-9]|$)')
{
fixed = "1.6.2.16.1";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
else
{
# Recommend lowest patched version in the 1.6.2 branch.
fixed = "1.6.2.15.1";
vulnerable = ver_compare(ver:version, fix:"1.6.2.17", app:"asterisk");
}
}
else
{
# Recommend lowest patched version in the 1.6 branch.
fixed = "1.6.1.21";
vulnerable = ver_compare(ver:version, fix:"1.6.3", app:"asterisk");
}
}
else if (version =~ '^1\\.8([^0-9]|$)')
{
if (version =~ '^1\\.8\\.1([^0-9]|$)')
{
fixed = "1.8.1.2";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
else if (version =~ '^1\\.8\\.2([^0-9]|$)')
{
fixed = "1.8.2.2";
vulnerable = ver_compare(ver:version, fix:fixed, app:"asterisk");
}
else
{
# Recommend lowest patched version in the 1.8 branch.
fixed = "1.8.1.2";
vulnerable = ver_compare(ver:version, fix:"1.8.3", app:"asterisk");
}
}
else if (version =~ '^[A-Z]')
{
fixed = "C.3.6.2";
if (version[0] <= "B")
{
vulnerable = -1;
}
else if (version[0] > "C")
{
vulnerable = 1;
}
else
{
tmp_fixed = substr(fixed, 2);
tmp_version = substr(version, 2);
vulnerable = ver_compare(ver:tmp_version, fix:tmp_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 if (installs == 1) audit(AUDIT_INST_VER_NOT_VULN, "Asterisk " + not_vuln_installs[0]);
else exit(0, "The Asterisk installs (" + join(not_vuln_installs, sep:", ") + ") are not affected.");
}