Vulnerability identifier: #VU11789
Vulnerability risk: Low
Exploitation vector: Network
Vendor: PHP Group
The vulnerability allows a remote attacker to obtain potentially sensitive information.
The weakness exists in the GIF decoding function gdImageCreateFromGifCtx in gd_gif_in.c due to it does not zero colorMap arrays before use. A remote attacker can trick the victim into opening a specially crafted GIF image that could use the uninitialized tables to read ~700 bytes from the top of the stack and gain access to potentially sensitive information.
Update to versions 5.6.31 or 7.1.7.
Vulnerable software versions
PHP: 5.6.0 - 5.6.30, 7.1.0 - 7.1.6
Fixed software versions
Can this vulnerability be exploited remotely?
Is there known malware, which exploits this vulnerability?