A flaw was found in GIMP's PSD file format plugin. This vulnerability, an unsigned integer underflow in the block_rem variable, occurs when a user opens a specially crafted .psd image file. The underflow leads to parser confusion, enabling an attacker to inject arbitrary data as layer resource blocks. This can ultimately result in arbitrary code execution, allowing the attacker to run malicious code on the victim's system.
To mitigate this vulnerability, users should avoid opening untrusted or suspicious PSD image files with GIMP. As a general security practice, it is recommended to only process image files from trusted sources.