Vulnerabilities > CVE-2016-9256 - Race Condition vulnerability in F5 products

047910
CVSS 6.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
f5
CWE-362
nessus
NVD
Published: 2017-05-09
Updated: 2017-05-16

Summary

In F5 BIG-IP 12.1.0 through 12.1.2, permissions enforced by iControl can lag behind the actual permissions assigned to a user if the role_map is not reloaded between the time the permissions are changed and the time of the user's next request. This is a race condition that occurs rarely in normal usage; the typical period in which this is possible is limited to at most a few seconds after the permission change.

Vulnerable Configurations

Part Description Count
Application
F5
40

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Leveraging Race Conditions
    This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.
  • Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
    This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. The typical example is the file access. The attacker can leverage a file access race condition by "running the race", meaning that he would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the attacker could do something such as replace the file and cause an escalation of privilege.

Nessus

NASL familyF5 Networks Local Security Checks
NASL idF5_BIGIP_SOL47284724.NASL
descriptionPermissions enforced by iControl can lag behind the actual permissions assigned to a user if the role_map is not reloaded between the time the permissions are changed and the time of the user
last seen2020-06-01
modified2020-06-02
plugin id97402
published2017-02-27
reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/97402
titleF5 Networks BIG-IP : iControl vulnerability (K47284724)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from F5 Networks BIG-IP Solution K47284724.
#
# The text description of this plugin is (C) F5 Networks.
#

include("compat.inc");

if (description)
{
  script_id(97402);
  script_version("3.9");
  script_cvs_date("Date: 2019/01/04 10:03:41");

  script_cve_id("CVE-2016-9256");

  script_name(english:"F5 Networks BIG-IP : iControl vulnerability (K47284724)");
  script_summary(english:"Checks the BIG-IP version.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote device is missing a vendor-supplied security patch."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Permissions enforced by iControl can lag behind the actual permissions
assigned to a user if the role_map is not reloaded between the time
the permissions are changed and the time of the user's next request.
This is a race condition that occurs rarely in normal usage; the
typical period in which this is possible is limited to at most a few
seconds after the permission change. (CVE-2016-9256)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://support.f5.com/csp/article/K47284724"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade to one of the non-vulnerable versions listed in the F5
Solution K47284724."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/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:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_access_policy_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_advanced_firewall_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_acceleration_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_security_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_visibility_and_reporting");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_link_controller");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_local_traffic_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_policy_enforcement_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/h:f5:big-ip");

  script_set_attribute(attribute:"patch_publication_date", value:"2017/02/24");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/02/27");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"F5 Networks Local Security Checks");

  script_dependencies("f5_bigip_detect.nbin");
  script_require_keys("Host/local_checks_enabled", "Host/BIG-IP/hotfix", "Host/BIG-IP/modules", "Host/BIG-IP/version", "Settings/ParanoidReport");

  exit(0);
}


include("f5_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
version = get_kb_item("Host/BIG-IP/version");
if ( ! version ) audit(AUDIT_OS_NOT, "F5 Networks BIG-IP");
if ( isnull(get_kb_item("Host/BIG-IP/hotfix")) ) audit(AUDIT_KB_MISSING, "Host/BIG-IP/hotfix");
if ( ! get_kb_item("Host/BIG-IP/modules") ) audit(AUDIT_KB_MISSING, "Host/BIG-IP/modules");

sol = "K47284724";
vmatrix = make_array();

if (report_paranoia < 2) audit(AUDIT_PARANOID);

# AFM
vmatrix["AFM"] = make_array();
vmatrix["AFM"]["affected"  ] = make_list("12.0.0-12.1.2");
vmatrix["AFM"]["unaffected"] = make_list("13.0.0","12.1.2HF1","11.4.0-11.6.1");

# AM
vmatrix["AM"] = make_array();
vmatrix["AM"]["affected"  ] = make_list("12.0.0-12.1.2");
vmatrix["AM"]["unaffected"] = make_list("13.0.0","12.1.2HF1","11.4.0-11.6.1");

# APM
vmatrix["APM"] = make_array();
vmatrix["APM"]["affected"  ] = make_list("12.0.0-12.1.2");
vmatrix["APM"]["unaffected"] = make_list("13.0.0","12.1.2HF1","11.4.0-11.6.1","11.2.1");

# ASM
vmatrix["ASM"] = make_array();
vmatrix["ASM"]["affected"  ] = make_list("12.0.0-12.1.2");
vmatrix["ASM"]["unaffected"] = make_list("13.0.0","12.1.2HF1","11.4.0-11.6.1","11.2.1");

# AVR
vmatrix["AVR"] = make_array();
vmatrix["AVR"]["affected"  ] = make_list("12.0.0-12.1.2");
vmatrix["AVR"]["unaffected"] = make_list("13.0.0","12.1.2HF1","11.4.0-11.6.1","11.2.1");

# LC
vmatrix["LC"] = make_array();
vmatrix["LC"]["affected"  ] = make_list("12.0.0-12.1.2");
vmatrix["LC"]["unaffected"] = make_list("13.0.0","12.1.2HF1","11.4.0-11.6.1","11.2.1");

# LTM
vmatrix["LTM"] = make_array();
vmatrix["LTM"]["affected"  ] = make_list("12.0.0-12.1.2");
vmatrix["LTM"]["unaffected"] = make_list("13.0.0","12.1.2HF1","11.4.0-11.6.1","11.2.1");

# PEM
vmatrix["PEM"] = make_array();
vmatrix["PEM"]["affected"  ] = make_list("12.0.0-12.1.2");
vmatrix["PEM"]["unaffected"] = make_list("13.0.0","12.1.2HF1","11.4.0-11.6.1");


if (bigip_is_affected(vmatrix:vmatrix, sol:sol))
{
  if (report_verbosity > 0) security_warning(port:0, extra:bigip_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = bigip_get_tested_modules();
  audit_extra = "For BIG-IP module(s) " + tested + ",";
  if (tested) audit(AUDIT_INST_VER_NOT_VULN, audit_extra, version);
  else audit(AUDIT_HOST_NOT, "running any of the affected modules");
}

References