Vulnerabilidades do Red Hat Red Hat Enterprise Linux 9

A vulnerability in the GRUB2 bootloader has been identified in the normal module. This flaw, a memory Use After Free issue, occurs because the normal_exit 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 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 An attacker who can execute this command can force the system to access memory locations that are no longer valid.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 has been identified in the GRUB (Grand Unified Bootloader) component. This flaw occurs because the bootloader mishandles string conversion when reading information from a USB device, allowing an attacker to exploit inconsistent length values. A local attacker can connect a maliciously configured USB device during the boot sequence to trigger this issue. A successful exploitation may lead GRUB to crash, leading to a Denial of Service. Data corruption may be also possible, although given the complexity of the exploit the impact is most likely limited.

A use-after-free vulnerability has been identified in the GNU GRUB (Grand Unified Bootloader). The flaw occurs because the file-closing process incorrectly retains a memory pointer, leaving an invalid reference to a file system structure. 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 net_set_vlan 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 An attacker who can execute this command can force the system to access memory locations that are no longer valid.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

A flaw was found in libvirt. External inactive snapshots for shut-down VMs are incorrectly created as world-readable, making it possible for unprivileged users to inspect the guest OS contents. This results in an information disclosure vulnerability.

If an attacker causes kdcproxy to connect to an attacker-controlled KDC server (e.g. through server-side request forgery), they can exploit the fact that kdcproxy does not enforce bounds on TCP response length to conduct a denial-of-service attack. While receiving the KDC's response, kdcproxy copies the entire buffered stream into a new buffer on each recv() call, even when the transfer is incomplete, causing excessive memory allocation and CPU usage. Additionally, kdcproxy accepts incoming response chunks as long as the received data length is not exactly equal to the length indicated in the response header, even when individual chunks or the total buffer exceed the maximum length of a Kerberos message. This allows an attacker to send unbounded data until the connection timeout is reached (approximately 12 seconds), exhausting server memory or CPU resources. Multiple concurrent requests can cause accept queue overflow, denying service to legitimate clients.

A flaw was discovered in libvirt in the XML file processing. More specifically, the parsing of user provided XML files was performed before the ACL checks. A malicious user with limited permissions could exploit this flaw by submitting a specially crafted XML file, causing libvirt to allocate too much memory on the host. The excessive memory consumption could lead to a libvirt process crash on the host, resulting in a denial-of-service condition.

A stack-based buffer overflow was found in the QEMU e1000 network device. The code for padding short frames was dropped from individual network devices and moved to the net core code. The issue stems from the device's receive code still being able to process a short frame in loopback mode. This could lead to a buffer overrun in the e1000_receive_iov() function via the loopback code path. A malicious guest user could use this vulnerability to crash the QEMU process on the host, resulting in a denial of service.

A data corruption vulnerability has been identified in the luksmeta utility when used with the LUKS1 disk encryption format. An attacker with the necessary permissions can exploit this flaw by writing a large amount of metadata to an encrypted device. The utility fails to correctly validate the available space, causing the metadata to overwrite and corrupt the user's encrypted data. This action leads to a permanent loss of the stored information. Devices using the LUKS formats other than LUKS1 are not affected by this issue.

A flaw was found in Samba, in the vfs_streams_xattr module, where uninitialized heap memory could be written into alternate data streams. This allows an authenticated user to read residual memory content that may include sensitive data, resulting in an information disclosure vulnerability.

A use-after-free vulnerability was found in libxslt while parsing xsl nodes that may lead to the dereference of expired pointers and application crash.