A flaw was found in grub2 when handling split HTTP headers. While processing a split HTTP header, grub2 wrongly advances its control pointer to the internal buffer by one position, which can lead to an out-of-bounds write. This flaw allows an attacker to leverage this issue by crafting a malicious set of HTTP packages making grub2 corrupt its internal memory metadata structure. This leads to data integrity and confidentiality issues or forces grub to crash, resulting in a denial of service attack.
A flaw was found in grub2 when handling IPv4 packets. This flaw allows an attacker to craft a malicious packet, triggering an integer underflow in grub code. Consequently, the memory allocation for handling the packet data may be smaller than the size needed. This issue causes an out-of-bands write during packet handling, compromising data integrity, confidentiality issues, a denial of service, and remote code execution.
A use-after-free vulnerability was found on grub2's chainloader command. This flaw allows an attacker to gain access to restricted data or cause arbitrary code execution if they can establish control from grub's memory allocation pattern.
A flaw was found in grub2. The shimlock verifier from grub2 allows non-kernel files to be loaded when secure boot is enabled, giving the possibility of unverified code or modules to be loaded when it should not be allowed.
A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.
A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform some triage over the heap layout to achieve signifcant results, also the values written into the memory are repeated three times in a row making difficult to produce valid payloads. This flaw affects grub2 versions prior grub-2.12.
A flaw was found in grub2 when handling a PNG image header. When decoding the data contained in the Huffman table at the PNG file header, an out-of-bounds write may happen on grub's heap.