Vulnerabilidades de Gnome

A stack-based buffer overflow vulnerability exists in the Dia diagram editor when processing Network Bus objects from Dia XML project files. In objects/network/bus.c, bus_load() reads the number of bus handles from the file attribute "bus_handles" using attribute_num_data() without validating an upper bound: bus->num_handles = attribute_num_data(attr); When a bus handle is subsequently moved, bus_handle_moved() allocates two temporary arrays on the stack: parallel = (real *)g_alloca(num_handles * sizeof(real)); perp = (real *)g_alloca(num_handles * sizeof(real)); Because num_handles is fully attacker-controlled via the project file, sufficiently large values (for example 262144 or higher) cause g_alloca() to consume more stack space than the default thread stack limit (typically 8 MB on Linux), resulting in stack overflow, SIGSEGV, and potential stack frame / return-address corruption. An attacker can embed a Bus object with an excessive bus_handles count in a malicious .dia file. Exploitation requires the victim to open the file in Dia (file dialog, command line, or file association) and trigger handle manipulation (moving a bus handle), which exercises the vulnerable code path. The identical g_alloca pattern is present in objects/Misc/tree.c (copied from bus.c) and is likely vulnerable to the same class of attack via Tree objects. Affected versions: Dia 0.98.0 and earlier versions containing this code; issue confirmed on upstream master as of 2026-08-21. Upstream report: https://gitlab.gnome.org/GNOME/dia/-/issues/581

A flaw was found in the file-pcx plugin in GIMP, affecting 32-bit builds only. When processing a PCX image file, the plugin calculates memory allocation sizes based on the image dimensions and the number of color planes. If a crafted file sets the number of planes to 4 alongside sufficiently large dimensions, the calculation exceeds the 32-bit integer limit and overflows, resulting in an undersized heap-based buffer allocation. This integer overflow issue results in a heap-based buffer overflow when the plugin subsequently writes image data into the undersized buffer, causing memory corruption, potentially leading to arbitrary code execution or a denial of service.

A flaw was found in the file-icns plugin in GIMP. When applying a decompressed mask during ICNS image processing, the plugin reads from the mask data buffer without verifying if the cursor exceeds the allocated resource size. If a crafted file contains a truncated mask resource, the icns_decompress function continues reading past the bounds of the buffer. This out-of-bounds read vulnerability results in information disclosure of heap contents, where memory contents are leaked as alpha channel pixel values, or a crash leading to a denial of service if unmapped memory is accessed.

A flaw was found in the file-fits plugin in GIMP. When processing a FITS image file, the plugin calculates memory allocation sizes using signed 32-bit integers for width and height. If a crafted file sets both values to large values, their product exceeds 2^31 and overflows, resulting in an undersized heap-based buffer allocation. This integer overflow issue results in a heap-based buffer overflow when cfitsio subsequently writes a full row of pixels in the buffer, causing memory corruption, potentially leading to arbitrary code execution or a denial of service.

A flaw was found in libsoup. The chunked transfer encoding parser uses a permissive parsing function for chunk sizes that silently accepts inputs violating RFC 9112, including leading whitespace, plus sign prefixes, and trailing invalid characters. When libsoup operates behind a strict frontend proxy, this parsing differential can be exploited to smuggle HTTP requests.

A flaw was found in GLib. The D-Bus client-side implementation of the DBUS_COOKIE_SHA1 SASL authentication mechanism does not validate the cookie_context parameter received from the server. A malicious D-Bus server can supply a cookie_context containing path traversal sequences, causing the client to read an arbitrary file and exfiltrate sensitive data by verifying guessed file contents against a generated hash.

A flaw was found in GLib. An off-by-one error can occur in the g_key_file_get_locale_string_list function in the gkeyfile.c file when loading a key file with an empty value. This flaw can cause an out-of-bounds access of 1 byte or a denial of service when the out-of-bounds access crosses a page boundary.

A flaw was found in GLib. A buffer over-read can occur in g_io_channel_read_line_backend() in the giochannel.c file when a custom line terminator with a length greater than one is set, causing memcmp to read past the GString buffer. This vulnerability can cause a minor information disclosure of 7 bytes or a denial of service when the buffer over-read crosses a page boundary.

A flaw was found in GLib. A buffer over-read can occur in the g_regex_replace function when used with the `G_REGEX_RAW` compile flag and case-change replacement escapes because the string_append function processes matched substrings using UTF-8 functions that assume valid UTF-8 input, even when the string is treated as raw bytes. This vulnerability can cause a minor information disclosure of 1-5 bytes and a denial of service when the buffer over-read crosses a page boundary.

A flaw was found in GLib. An out-of-bounds read of only 2 bytes can occur in the g_date_time_get_ymd function in the glib/gdatetime.c file when an invalid GDateTime object produced by the g_date_time_add_full function is processed. This flaw can corrupt the date output and potentially cause logic errors that may lead to a denial of service.

A flaw was found in GLib. An off-by-one error can occur in the gvs_tuple_is_normal function in the glib/gvariant-serialiser.c file when doing an alignment padding check because the bounds check uses > instead of >=, causing an out-of-bounds read of only 1 byte. This issue can cause a minor information disclosure of 1 byte and a denial of service when the out-of-bounds read crosses a page boundary.