A flaw exists in gdk‑pixbuf within the gdk_pixbuf__jpeg_image_load_increment function (io-jpeg.c) and in glib’s g_base64_encode_step (glib/gbase64.c). When processing maliciously crafted JPEG images, a heap buffer overflow can occur during Base64 encoding, allowing out-of-bounds reads from heap memory, potentially causing application crashes or arbitrary code execution.
Credits
Red Hat would like to thank Yifan Zhang (Programming Languages Lab, Peking University) for reporting this issue.