CVE-2025-6199: Gdk-pixbuf: uninitialized memory disclosure in gdkpixbuf gif lzw decoder
A flaw was found in the GIF parser of GdkPixbuf’s LZW decoder. When an invalid symbol is encountered during decompression, the decoder sets the reported output size to the full buffer length rather than the actual number of written bytes. This logic error results in uninitialized sections of the buffer being included in the output, potentially leaking arbitrary memory contents in the processed image.
Other sources
Gdk-pixbuf: uninitialized memory disclosure in gdkpixbuf gif lzw decoder
— Microsoft
Information Disclosure via uninitialized heap memory exposure in GdkPixbuf’s GIF LZW decoder. Upon encountering an invalid LZW symbol, the decoder incorrectly returns the full buffer length instead of the number of decoded bytes written. This oversight leads to uninitialized memory regions in the output image. A crafted GIF can be used to leak memory contents by processing and then reading back the resulting pixbuf.
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 2.40.0-7 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 2.42.10-3
Event History
Frequently Asked Questions
What is the severity of CVE-2025-6199?
CVE-2025-6199 has a severity rating that indicates it could lead to potential security risks due to the flawed GIF parser.
How do I fix CVE-2025-6199?
To fix CVE-2025-6199, update to the latest version of GdkPixbuf that addresses the GIF parser vulnerability.
What systems are affected by CVE-2025-6199?
CVE-2025-6199 affects systems using GdkPixbuf with the LZW decoder for GIF images.
What could happen if CVE-2025-6199 is exploited?
If exploited, CVE-2025-6199 may allow attackers to access uninitialized memory, potentially leaking sensitive information.
Is there a workaround for CVE-2025-6199?
A temporary workaround for CVE-2025-6199 may involve disabling the use of the GIF decoder until a fix is applied.