saitoha CVE Vulnerabilities & Metrics

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. In versions 1.8.7 and prior, when built with the --with-gdk-pixbuf2 option, a use-after-free vulnerability exists in load_with_gdkpixbuf() in loader.c. The cleanup path manually frees the sixel_frame_t object and its internal buffers without consulting the reference count, even though the object was created via the refcounted constructor sixel_frame_new() and exposed to the public callback. A callback that calls sixel_frame_ref(frame) to retain a logically valid reference will hold a dangling pointer after sixel_helper_load_image_file() returns, and any subsequent access to the frame or its fields triggers a use-after-free confirmed by AddressSanitizer. The root cause is a consistency failure between two cleanup strategies in the same codebase: sixel_frame_unref() is used in load_with_builtin() but raw free() is used in load_with_gdkpixbuf(). An attacker supplying a crafted image to any application built against libsixel with gdk-pixbuf2 support can trigger this reliably, potentially leading to information disclosure, memory corruption, or code execution. This issue has been fixed in version 1.8.7-r1.

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a use-after-free vulnerability in sixel_encoder_encode_bytes() because sixel_frame_init() stores the caller-owned pixel buffer pointer directly in frame->pixels without making a defensive copy. When a resize operation is triggered, sixel_frame_convert_to_rgb888() unconditionally frees this caller-owned buffer and replaces it with a new internal allocation, leaving the caller with a dangling pointer. Any subsequent access to the original buffer by the caller constitutes a use-after-free, confirmed by AddressSanitizer. An attacker who controls incoming frames can trigger this bug repeatedly and predictably, resulting in a reliable crash with potential for code execution. This issue has been fixed in version 1.8.7-r1.

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow which leads to a heap buffer overflow via sixel_frame_convert_to_rgb888() in frame.c, where allocation size and pointer offset computations for palettised images (PAL1, PAL2, PAL4) are performed using int arithmetic before casting to size_t. For images whose pixel count exceeds INT_MAX / 4, the overflow produces an undersized heap allocation for the conversion buffer and a negative pointer offset for the normalization sub-buffer, after which sixel_helper_normalize_pixelformat() writes the full image data starting from the invalid pointer, causing massive heap corruption confirmed by ASAN. An attacker providing a specially crafted large palettised PNG can corrupt the heap of the victim process, resulting in a reliable crash and potential arbitrary code execution. This issue has been fixed in version 1.8.7-r1.

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INT_MAX are accepted without overflow-safe bounds checking. In sixel_encoder_do_clip(), the expression clip_w + clip_x overflows to a large negative value when clip_x is INT_MAX, causing the bounds guard to be skipped entirely, and the unclamped coordinate is passed through sixel_frame_clip() to clip(), which computes a source pointer far beyond the image buffer and passes it to memmove(). An attacker supplying a specially crafted crop argument with any valid image can trigger an out-of-bounds read in the heap, resulting in a reliable crash and potential information disclosure. This issue has been fixed in version 1.8.7-r1.

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a Use-After-Free vulnerability via the load_gif() function in fromgif.c, where a single sixel_frame_t object is reused across all frames of an animated GIF and gif_init_frame() unconditionally frees and reallocates frame->pixels between frames without consulting the object's reference count. Because the public API explicitly provides sixel_frame_ref() to retain a frame and sixel_frame_get_pixels() to access the raw pixel buffer, a callback following this documented usage pattern will hold a dangling pointer after the second frame is decoded, resulting in a heap use-after-free confirmed by ASAN. Any application using sixel_helper_load_image_file() with a multi-frame callback to process user-supplied animated GIFs is affected, with a reliable crash as the minimum impact and potential for code execution. This issue has been fixed in version 1.8.7-r1.

A vulnerability was found in saitoha libsixel up to 1.10.3. Affected by this issue is the function sixel_debug_print_palette of the file src/encoder.c of the component img2sixel. The manipulation results in stack-based buffer overflow. The attack must be initiated from a local position. The exploit has been made public and could be used. The patch is identified as 316c086e79d66b62c0c4bc66229ee894e4fdb7d1. Applying a patch is advised to resolve this issue.

There is a floating point exception error in sixel_encoder_do_resize, encoder.c:633 in libsixel img2sixel 1.8.6. Remote attackers could leverage this vulnerability to cause a denial-of-service via a crafted JPEG file.

There is an assertion failure error in stbi__jpeg_huff_decode, stb_image.h:1894 in libsixel img2sixel 1.8.6. Remote attackers could leverage this vulnerability to cause a denial-of-service via a crafted JPEG file.

libsixel 1.8.6 suffers from a Heap Use After Free vulnerability in in libsixel/src/dither.c:388.

libsixel 1.8.6 is affected by Buffer Overflow in libsixel/src/quant.c:876.

stb_image.h (aka the stb image loader) 2.19, as used in libsixel and other products, has a reachable assertion in stbi__create_png_image_raw.

In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.

Libsixel 1.8.3 contains a heap-based buffer overflow in the sixel_encode_highcolor function in tosixel.c.

Libsixel 1.8.2 contains a heap-based buffer overflow in the dither_func_fs function in tosixel.c.

Libsixel prior to v1.8.3 contains a stack buffer overflow in the function gif_process_raster at fromgif.c.

An invalid read in the stb_image.h component of libsixel prior to v1.8.5 allows attackers to cause a denial of service (DOS) via a crafted PSD file.

An issue in the dither.c component of libsixel prior to v1.8.4 allows attackers to cause a denial of service (DOS) via a crafted PNG file.

A heap-based buffer overflow in the sixel_encoder_output_without_macro function in encoder.c of Libsixel 1.8.4 allows attackers to cause a denial of service (DOS) via converting a crafted PNG file into Sixel format.

Buffer Overflow in the "sixel_encoder_encode_bytes" function of Libsixel v1.8.6 allows attackers to cause a Denial of Service (DoS).

Unverified indexs into the array lead to out of bound access in the gif_out_code function in fromgif.c in libsixel 1.8.6.

load_png in loader.c in libsixel.a in libsixel 1.8.6 has an uninitialized pointer leading to an invalid call to free, which can cause a denial of service.

libsixel 1.8.4 has an integer overflow in sixel_frame_resize in frame.c.

An issue was discovered in libsixel 1.8.4. There is a heap-based buffer overflow in the function gif_out_code at fromgif.c.

An issue was discovered in libsixel 1.8.4. There is a heap-based buffer overflow in the function gif_init_frame at fromgif.c.

A heap-based buffer overflow was discovered in image_buffer_resize in fromsixel.c in libsixel before 1.8.4.

A memory leak was discovered in image_buffer_resize in fromsixel.c in libsixel 1.8.4.

An invalid memory address dereference was discovered in load_pnm in frompnm.c in libsixel before 1.8.3.

An issue was discovered in libsixel 1.8.2. There is a heap-based buffer over-read in the function load_sixel at loader.c.

stb_image.h (aka the stb image loader) 2.23, as used in libsixel and other products, has a heap-based buffer over-read in stbi__load_main.

An issue was discovered in libsixel 1.8.2. There is a heap-based buffer overflow in the function load_pnm at frompnm.c, due to an integer overflow.

An issue was discovered in libsixel 1.8.2. There is an integer overflow in the function sixel_decode_raw_impl at fromsixel.c.

An issue was discovered in libsixel 1.8.2. There is an integer overflow in the function sixel_encode_body at tosixel.c.

An issue was discovered in libsixel 1.8.2. There is a heap-based buffer overflow in the function sixel_decode_raw_impl at fromsixel.c.

The load_pnm function in frompnm.c in libsixel.a in libsixel 1.8.2 has infinite recursion.

In libsixel v1.8.2, there is a heap-based buffer over-read in the function load_jpeg() in the file loader.c, as demonstrated by img2sixel.

In libsixel v1.8.2, there is an infinite loop in the function sixel_decode_raw_impl() in the file fromsixel.c, as demonstrated by sixel2png.

There is a heap-based buffer over-read at writer.c (function: write_png_to_file) in libsixel 1.8.2 that will cause a denial of service.

There is a heap-based buffer overflow at fromsixel.c (function: image_buffer_resize) in libsixel 1.8.2 that will cause a denial of service or possibly unspecified other impact.

There is an illegal address access at fromsixel.c (function: sixel_decode_raw_impl) in libsixel 1.8.2 that will cause a denial of service.

There is a heap-based buffer over-read at stb_image_write.h (function: stbi_write_png_to_mem) in libsixel 1.8.2 that will cause a denial of service.

There is a NULL pointer dereference at function sixel_helper_set_additional_message (status.c) in libsixel 1.8.2 that will cause a denial of service.

There is a heap-based buffer over-read at stb_image.h (function: stbi__tga_load) in libsixel 1.8.2 that will cause a denial of service.

libsixel 1.8.1 has a memory leak in sixel_allocator_new in allocator.c.

libsixel 1.8.1 has a memory leak in sixel_decoder_decode in decoder.c, image_buffer_resize in fromsixel.c, and sixel_decode_raw in fromsixel.c.