CVE-2018-14553 : Security Advisory and Response

A vulnerability in the libgd library versions 2.1.0-rc2 through 2.2.5 can lead to a NULL pointer dereference, potentially causing application crashes. This CVE affects PHP when linked with an external libgd library.

Understanding CVE-2018-14553

The function gdImageClone in gd.c within the libgd library versions 2.1.0-rc2 through 2.2.5 is vulnerable to a NULL pointer dereference, which attackers can exploit to crash applications using a specific function call sequence.

What is CVE-2018-14553?

gdImageClone in gd.c within the libgd library versions 2.1.0-rc2 through 2.2.5 is susceptible to a NULL pointer dereference, allowing attackers to crash applications by utilizing a specific sequence of function calls.

The Impact of CVE-2018-14553

This vulnerability can be exploited by attackers to cause a crash in an application by using a specific sequence of function calls. It is crucial to note that this vulnerability only affects PHP when it is linked with an external libgd library and not when bundled.

Technical Details of CVE-2018-14553

The technical details of the CVE-2018-14553 vulnerability are as follows:

Vulnerability Description

The vulnerability lies in the gdImageClone function in gd.c within the libgd library versions 2.1.0-rc2 through 2.2.5, leading to a NULL pointer dereference.

Affected Systems and Versions

Affected versions: 2.1.0-rc2 through 2.2.5
Systems using PHP linked with an external libgd library

Exploitation Mechanism

Attackers can exploit this vulnerability by using a specific sequence of function calls to trigger a crash in the application.

Mitigation and Prevention

To mitigate the risks associated with CVE-2018-14553, consider the following steps:

Immediate Steps to Take

Update libgd library to a non-vulnerable version
Monitor vendor advisories for patches and updates

Long-Term Security Practices

Regularly update software and libraries to the latest secure versions
Implement secure coding practices to prevent NULL pointer dereference vulnerabilities

Patching and Updates

Apply patches provided by the libgd library or PHP to address the vulnerability