CVE-2017-7890 : What You Need to Know
Learn about CVE-2017-7890, a vulnerability in the GD Graphics Library affecting PHP versions before 5.6.31 and 7.x. Find out how to mitigate the risk and prevent sensitive information disclosure.
A vulnerability in the GIF decoding function gdImageCreateFromGifCtx in the GD Graphics Library (libgd) affects PHP versions prior to 5.6.31 and 7.x before 7.1.7, potentially leading to sensitive information disclosure.
Understanding CVE-2017-7890
What is CVE-2017-7890?
The vulnerability lies in the improper initialization of colorMap arrays in the GD Graphics Library, allowing attackers to read stack memory by crafting a malicious GIF image.
The Impact of CVE-2017-7890
The vulnerability could enable attackers to disclose sensitive information by exploiting the uninitialized colorMap arrays.
Technical Details of CVE-2017-7890
Vulnerability Description
- The vulnerability exists in the GIF decoding function gdImageCreateFromGifCtx in the GD Graphics Library.
- It affects PHP versions prior to 5.6.31 and 7.x before 7.1.7.
Affected Systems and Versions
- PHP versions before 5.6.31 and 7.x before 7.1.7 are vulnerable.
Exploitation Mechanism
- Attackers can exploit this vulnerability by creating a specially crafted GIF image to read stack memory.
Mitigation and Prevention
Immediate Steps to Take
- Update PHP to version 5.6.31 or 7.1.7 or later to mitigate the vulnerability.
- Monitor for any unusual activities that could indicate exploitation of the vulnerability.
Long-Term Security Practices
- Regularly update software and libraries to the latest versions to address known vulnerabilities.
Patching and Updates
- Apply patches provided by PHP to fix the vulnerability.