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 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 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. Grub's dump command is not blocked when grub is in lockdown mode, which allows the user to read any memory information, and an attacker may leverage this in order to extract signatures, salts, and other sensitive information from the memory.

A vulnerability has been identified in the GRUB2 bootloader's normal command that poses an immediate Denial of Service (DoS) risk. This flaw is a Use-after-Free issue, caused because the normal command is not properly unregistered when the module is unloaded. An attacker who can execute this command can force the system to access memory locations that are no longer valid. Successful exploitation leads directly to system instability, which can result in a complete crash and halt system availability. Impact on the data integrity and confidentiality is also not discarded.

A vulnerability in the GRUB2 bootloader has been identified in the normal module. This flaw, a memory Use After Free issue, occurs because the normalexit command is not properly unregistered when its related module is unloaded. An attacker can exploit this condition by invoking the command after the module has been removed, causing the system to improperly access a previously freed memory location. This leads to a system crash or possible impacts in data confidentiality and integrity.

A Use-After-Free vulnerability has been discovered in GRUB's gettext module. This flaw stems from a programming error where the gettext command remains registered in memory after its module is unloaded. An attacker can exploit this condition by invoking the orphaned command, causing the application to access a memory location that is no longer valid. An attacker could exploit this vulnerability to cause grub to crash, leading to a Denial of Service. Possible data integrity or confidentiality compromise is not discarded.

A vulnerability has been identified in the GRUB2 bootloader's network module that poses an immediate Denial of Service (DoS) risk. This flaw is a Use-after-Free issue, caused because the netsetvlan command is not properly unregistered when the network module is unloaded from memory. An attacker who can execute this command can force the system to access memory locations that are no longer valid. Successful exploitation leads directly to system instability, which can result in a complete crash and halt system availability

An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved.

An out-of-bounds read flaw was found on grub2's NTFS filesystem driver. This issue may allow a physically present attacker to present a specially crafted NTFS file system image to read arbitrary memory locations. A successful attack allows sensitive data cached in memory or EFI variable values to be leaked, presenting a high Confidentiality risk.

An authentication bypass flaw was found in GRUB due to the way that GRUB uses the UUID of a device to search for the configuration file that contains the password hash for the GRUB password protection feature. An attacker capable of attaching an external drive such as a USB stick containing a file system with a duplicate UUID (the same as in the "/boot/" file system) can bypass the GRUB password protection feature on UEFI systems, which enumerate removable drives before non-removable ones. This issue was introduced in a downstream patch in Red Hat's version of grub2 and does not affect the upstream package.

A flaw was found in grub2. When failing to mount an HFS+ grub, the hfsplus filesystem driver doesn't properly set an ERRNO value. This issue may lead to a NULL pointer access.

A flaw was found in grub2. When reading data from a squash4 filesystem, grub's squash4 fs module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grubmalloc() operation with a smaller size than expected. As a result, the directread() will perform a heap based out-of-bounds write during data reading. This flaw may be leveraged to corrupt grub's internal critical data and may result in arbitrary code execution, by-passing secure boot protections.

A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grubmalloc() operation with a smaller size than expected. As a result, the grubromfsreadsymlink() may cause out-of-bounds writes when the calling grubdiskread() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passing secure boot protections.

A flaw was found in grub2. When reading tar files, grub2 allocates an internal buffer for the file name. However, it fails to properly verify the allocation against possible integer overflows. It's possible to cause the allocation length to overflow with a crafted tar file, leading to a heap out-of-bounds write. This flaw eventually allows an attacker to circumvent secure boot protections.

A flaw was found in grub2. When reading a symbolic link's name from a UFS filesystem, grub2 fails to validate the string length taken as an input. The lack of validation may lead to a heap out-of-bounds write, causing data integrity issues and eventually allowing an attacker to circumvent secure boot protections.

A stack overflow flaw was found when reading a BFS file system. A crafted BFS filesystem may lead to an uncontrolled loop, causing grub2 to crash.

A flaw was found in grub2. When reading data from a jfs filesystem, grub's jfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciouly crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grubmalloc() operation with a smaller size than expected. As a result, the grubjfslookupsymlink() function will write past the internal buffer length during grubjfsreadfile(). This issue can be leveraged to corrupt grub's internal critical data and may result in arbitrary code execution, by-passing secure boot protections.

An integer overflow flaw was found in the BFS file system driver in grub2. When reading a file with an indirect extent map, grub2 fails to validate the number of extent entries to be read. A crafted or corrupted BFS filesystem may cause an integer overflow during the file reading, leading to a heap of bounds read. As a consequence, sensitive data may be leaked, or grub2 will crash.

A flaw was found in grub2. The calculation of the translation buffer when reading a language .mo file in grubgettextgetstrfromposition() may overflow, leading to a Out-of-bound write. This issue can be leveraged by an attacker to overwrite grub2's sensitive heap data, eventually leading to the circumvention of secure boot protections.

A flaw was found in grub2. A specially crafted JPEG file can cause the JPEG parser of grub2 to incorrectly check the bounds of its internal buffers, resulting in an out-of-bounds write. The possibility of overwriting sensitive information to bypass secure boot protections is not discarded.

A flaw was found in grub2. When performing a symlink lookup from a reiserfs filesystem, grub's reiserfs fs module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciouly crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grubmalloc() operation with a smaller size than expected. As a result, the grubreiserfsreadsymlink() will call grubreiserfsreadreal() with a overflown length parameter, leading to a heap based out-of-bounds write during data reading. This flaw may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution, by-passing secure boot protections.

A flaw was found in grub2 where the grubextcmddispatcher() function calls grubarglistalloc() to allocate memory for the grub's argument list. However, it fails to check in case the memory allocation fails. Once the allocation fails, a NULL point will be processed by the parseoption() function, leading grub to crash or, in some rare scenarios, corrupt the IVT data.

A flaw was found in command/gpg. In some scenarios, hooks created by loaded modules are not removed when the related module is unloaded. This flaw allows an attacker to force grub2 to call the hooks once the module that registered it was unloaded, leading to a use-after-free vulnerability. If correctly exploited, this vulnerability may result in arbitrary code execution, eventually allowing the attacker to bypass secure boot protections.

A flaw was found in the HFS filesystem. When reading an HFS volume's name at grubfsmount(), the HFS filesystem driver performs a strcpy() using the user-provided volume name as input without properly validating the volume name's length. This issue may read to a heap-based out-of-bounds writer, impacting grub's sensitive data integrity and eventually leading to a secure boot protection bypass.

Grub2: udf: heap based buffer overflow in grubudfreadblock() may lead to arbitrary code execution

Grub2: fs/hfs: integer overflow may lead to heap based out-of-bounds write

When reading language .mo file in grubmofileopen(), grub2 fails to verify to a integer overflow when allocating its internal buffer. A crafted .mo file may lead to the buffer size calculation to overflow leading to Out-of-bound reads and writes. An attacker may leverage this flaw to leak sensitive data or overwrite critical data possibly leading to the circumvention of secure boot protections.

A flaw was found in the grub2-set-bootflag utility of grub2. After the fix of CVE-2019-14865, grub2-set-bootflag will create a temporary file with the new grubenv content and rename it to the original grubenv file. If the program is killed before the rename operation, the temporary file will not be removed and may fill the filesystem when invoked multiple times, resulting in a filesystem out of free inodes or blocks.