Vulnerabilities > CVE-2015-7748 - Improper Input Validation vulnerability in Juniper Junos

047910
CVSS 5.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
PARTIAL
network
low complexity
juniper
CWE-20
nessus

Summary

Juniper chassis with Trio (Trinity) chipset line cards and Junos OS 13.3 before 13.3R8, 14.1 before 14.1R6, 14.2 before 14.2R5, and 15.1 before 15.1R2 allow remote attackers to cause a denial of service (MPC line card crash) via a crafted uBFD packet.

Vulnerable Configurations

Part Description Count
OS
Juniper
21

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

NASL familyJunos Local Security Checks
NASL idJUNIPER_JSA10701.NASL
descriptionAccording to its self-reported version number, the remote Juniper Junos device is potentially affected by a denial of service vulnerability due to improper handling of uBFD packets that are received directly by chassis that have the
last seen2019-10-28
modified2015-10-26
plugin id86606
published2015-10-26
reporterThis script is Copyright (C) 2015-2018 Tenable Network Security, Inc.
sourcehttps://www.tenable.com/plugins/nessus/86606
titleJuniper Junos MX and T4000 Series Trinity uBFD Packet DoS (JSA10701)
code
#TRUSTED 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
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(86606);
  script_version("1.10");
  script_set_attribute(attribute:"plugin_modification_date", value:"2018/08/10");

  script_cve_id("CVE-2015-7748");
  script_xref(name:"JSA", value:"JSA10701");

  script_name(english:"Juniper Junos MX and T4000 Series Trinity uBFD Packet DoS (JSA10701)");
  script_summary(english:"Checks the Junos version, model, and configuration.");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version number, the remote Juniper
Junos device is potentially affected by a denial of service
vulnerability due to improper handling of uBFD packets that are
received directly by chassis that have the 'Trio Chipset' (Trinity)
MPC. A remote attacker can exploit this issue, via maliciously crafted
uBFD packets, to crash the MPC line card.");
  script_set_attribute(attribute:"see_also", value:"https://kb.juniper.net/InfoCenter/index?page=content&id=JSA10701");
  script_set_attribute(attribute:"solution", value:
"Apply the relevant Junos software release referenced in Juniper
advisory JSA10701.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");

  script_set_attribute(attribute:"vuln_publication_date", value:"2015/10/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2015/10/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/10/26");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:juniper:junos");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Junos Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2015-2018 Tenable Network Security, Inc.");

  script_dependencies("junos_version.nasl");
  script_require_keys("Host/Juniper/JUNOS/Version", "Host/Juniper/model", "Settings/ParanoidReport");

  exit(0);
}

include("audit.inc");
include("junos_kb_cmd_func.inc");
include("misc_func.inc");

ver   = get_kb_item_or_exit('Host/Juniper/JUNOS/Version');
model = get_kb_item_or_exit('Host/Juniper/model');

if (model !~ "(^MX[0-9]|^MX-MPC[1-4]|^EX9200|^CHAS-MX|^MPC[4-]|^T4000-)")
  audit(AUDIT_HOST_NOT, 'an MX Series, EX 9200 or T4000 router that supports Trio (Trinity) chipset line cards');

fixes = make_array();
fixes['13.3'   ] = '13.3R8';
fixes['14.1X50'] = '14.1X50-D110'; # PR1102581
fixes['14.1'   ] = '14.1R6';
fixes['14.2'   ] = '14.2R5';
fixes['15.1R'  ] = '15.1R2';
fixes['15.1F'  ] = '15.1F3';

fix = check_junos(ver:ver, fixes:fixes, exit_on_fail:TRUE);

# Label-Switched Interfaces (LSI) / Virtual Tunnel (VT) interfaces w/ MPLS IPv6
override = TRUE;
buf = junos_command_kb_item(cmd:"show configuration | display set");
if (buf)
{
  pattern = "^set protocols mpls ipv6-tunneling";
  if (junos_check_config(buf:buf, pattern:pattern))
  {
    pattern =
      "^set (logical-systems|routing-instances) .* (no-)?tunnel-services";
    foreach pattern (patterns)
      if (junos_check_config(buf:buf, pattern:pattern)) override = FALSE;
  }

  if (override) audit(AUDIT_INST_VER_NOT_VULN, 'Junos', ver);

  buf = junos_command_kb_item(cmd:"show chassis hardware");
  if (buf)
  {
    # Trio-based PFE modules part numbers
    #  https://kb.juniper.net/InfoCenter/index?page=content&id=KB25385
    part_numbers = make_list(
      "750-028381",
      "750-031087",
      "750-028395",
      "750-031092",
      "750-038489",
      "750-038490",
      "750-031089",
      "750-028393",
      "750-028391",
      "750-031088",
      "750-028394",
      "750-031090",
      "750-024884",
      "750-038491",
      "750-038493",
      "750-038492",
      "750-028467",
      "711-031594",
      "711-031603",
      "711-038215",
      "711-038213",
      "711-038211",
      "711-038634"
    );

    foreach part_number (part_numbers)
    {
      if (part_number >< buf)
      {
        override = FALSE;
        break;
      }
    }
    if (override) audit(AUDIT_HOST_NOT, 'affected because no Trio-based PFE modules were detected');
  }
}

junos_report(ver:ver, fix:fix, model:model, override:override, severity:SECURITY_WARNING);