CVE Vulnerabilities

CVE-2016-6290

Use After Free

Published: Jul 25, 2016 | Modified: Nov 07, 2023
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
4.4 MODERATE
AV:L/AC:M/Au:N/C:P/I:P/A:P
RedHat/V3
7 MODERATE
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM

ext/session/session.c in PHP before 5.5.38, 5.6.x before 5.6.24, and 7.x before 7.0.9 does not properly maintain a certain hash data structure, which allows remote attackers to cause a denial of service (use-after-free) or possibly have unspecified other impact via vectors related to session deserialization.

Weakness

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

Affected Software

Name Vendor Start Version End Version
Php Php * 5.5.37 (including)
Php Php 5.6.0-alpha1 (including) 5.6.0-alpha1 (including)
Php Php 5.6.0-alpha2 (including) 5.6.0-alpha2 (including)
Php Php 5.6.0-alpha3 (including) 5.6.0-alpha3 (including)
Php Php 5.6.0-alpha4 (including) 5.6.0-alpha4 (including)
Php Php 5.6.0-alpha5 (including) 5.6.0-alpha5 (including)
Php Php 5.6.0-beta1 (including) 5.6.0-beta1 (including)
Php Php 5.6.0-beta2 (including) 5.6.0-beta2 (including)
Php Php 5.6.0-beta3 (including) 5.6.0-beta3 (including)
Php Php 5.6.0-beta4 (including) 5.6.0-beta4 (including)
Php Php 5.6.1 (including) 5.6.1 (including)
Php Php 5.6.2 (including) 5.6.2 (including)
Php Php 5.6.3 (including) 5.6.3 (including)
Php Php 5.6.4 (including) 5.6.4 (including)
Php Php 5.6.5 (including) 5.6.5 (including)
Php Php 5.6.6 (including) 5.6.6 (including)
Php Php 5.6.7 (including) 5.6.7 (including)
Php Php 5.6.8 (including) 5.6.8 (including)
Php Php 5.6.9 (including) 5.6.9 (including)
Php Php 5.6.10 (including) 5.6.10 (including)
Php Php 5.6.11 (including) 5.6.11 (including)
Php Php 5.6.12 (including) 5.6.12 (including)
Php Php 5.6.13 (including) 5.6.13 (including)
Php Php 5.6.14 (including) 5.6.14 (including)
Php Php 5.6.15 (including) 5.6.15 (including)
Php Php 5.6.16 (including) 5.6.16 (including)
Php Php 5.6.17 (including) 5.6.17 (including)
Php Php 5.6.18 (including) 5.6.18 (including)
Php Php 5.6.19 (including) 5.6.19 (including)
Php Php 5.6.20 (including) 5.6.20 (including)
Php Php 5.6.21 (including) 5.6.21 (including)
Php Php 5.6.22 (including) 5.6.22 (including)
Php Php 5.6.23 (including) 5.6.23 (including)
Php Php 7.0.0 (including) 7.0.0 (including)
Php Php 7.0.1 (including) 7.0.1 (including)
Php Php 7.0.2 (including) 7.0.2 (including)
Php Php 7.0.3 (including) 7.0.3 (including)
Php Php 7.0.4 (including) 7.0.4 (including)
Php Php 7.0.5 (including) 7.0.5 (including)
Php Php 7.0.8 (including) 7.0.8 (including)
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-php56-0:2.3-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-php56-php-0:5.6.25-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6 RedHat rh-php56-php-pear-1:1.9.5-4.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS RedHat rh-php56-0:2.3-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS RedHat rh-php56-php-0:5.6.25-1.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS RedHat rh-php56-php-pear-1:1.9.5-4.el6 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-php56-0:2.3-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-php56-php-0:5.6.25-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-php56-php-pear-1:1.9.5-4.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS RedHat rh-php56-0:2.3-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS RedHat rh-php56-php-0:5.6.25-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUS RedHat rh-php56-php-pear-1:1.9.5-4.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS RedHat rh-php56-0:2.3-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS RedHat rh-php56-php-0:5.6.25-1.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS RedHat rh-php56-php-pear-1:1.9.5-4.el7 *
Php5 Ubuntu precise *
Php5 Ubuntu trusty *
Php5 Ubuntu trusty/esm *
Php5 Ubuntu wily *
Php7.0 Ubuntu devel *
Php7.0 Ubuntu esm-infra/xenial *
Php7.0 Ubuntu upstream *
Php7.0 Ubuntu xenial *

Extended Description

The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:

In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.

Potential Mitigations

References