CVE Vulnerabilities

CVE-2016-7413

Use After Free

Published: Sep 17, 2016 | Modified: May 04, 2018
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
RedHat/V3
Ubuntu

Use-after-free vulnerability in the wddx_stack_destroy function in ext/wddx/wddx.c in PHP before 5.6.26 and 7.x before 7.0.11 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a wddxPacket XML document that lacks an end-tag for a recordset field element, leading to mishandling in a wddx_deserialize call.

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 7.0.4 7.0.4
Php Php 7.0.3 7.0.3
Php Php 7.0.1 7.0.1
Php Php 7.0.7 7.0.7
Php Php * 5.6.25
Php Php 7.0.2 7.0.2
Php Php 7.0.9 7.0.9
Php Php 7.0.8 7.0.8
Php Php 7.0.5 7.0.5
Php Php 7.0.10 7.0.10
Php Php 7.0.0 7.0.0
Php Php 7.0.6 7.0.6

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