Redhat » Enterprise Linux Server Eus » 7.6 : Security Vulnerabilities, CVEs, CVSS score >= 1

A flaw was found in grub2 in versions prior to 2.06. Setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters which allows an attacker to corrupt memory by one byte for each quote in the input. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in grub2 in versions prior to 2.06. The option parser allows an attacker to write past the end of a heap-allocated buffer by calling certain commands with a large number of specific short forms of options. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub's memory layout. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. If the function is called with a command line that references a variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack frame and control execution which could also circumvent Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in grub2 in versions prior to 2.06. During USB device initialization, descriptors are read with very little bounds checking and assumes the USB device is providing sane values. If properly exploited, an attacker could trigger memory corruption leading to arbitrary code execution allowing a bypass of the Secure Boot mechanism. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in grub2 in versions prior to 2.06. The rmmod implementation allows the unloading of a module used as a dependency without checking if any other dependent module is still loaded leading to a use-after-free scenario. This could allow arbitrary code to be executed or a bypass of Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in grub2 in versions prior to 2.06, where it incorrectly enables the usage of the ACPI command when Secure Boot is enabled. This flaw allows an attacker with privileged access to craft a Secondary System Description Table (SSDT) containing code to overwrite the Linux kernel lockdown variable content directly into memory. The table is further loaded and executed by the kernel, defeating its Secure Boot lockdown and allowing the attacker to load unsigned code. The highest threat from this vulnerability is to data confidentiality and integrity, as well as system availability.

It was found that icedtea-web though 1.7.2 and 1.8.2 did not properly sanitize paths from <jar/> elements in JNLP files. An attacker could trick a victim into running a specially crafted application and use this flaw to upload arbitrary files to arbitrary locations in the context of the user.

The virConnectBaselineHypervisorCPU() and virConnectCompareHypervisorCPU() libvirt APIs, 4.x.x before 4.10.1 and 5.x.x before 5.4.1, accept an "emulator" argument to specify the program providing emulation for a domain. Since v1.2.19, libvirt will execute that program to probe the domain's capabilities. Read-only clients could specify an arbitrary path for this argument, causing libvirtd to execute a crafted executable with its own privileges.

The virConnectGetDomainCapabilities() libvirt API, versions 4.x.x before 4.10.1 and 5.x.x before 5.4.1, accepts an "emulatorbin" argument to specify the program providing emulation for a domain. Since v1.2.19, libvirt will execute that program to probe the domain's capabilities. Read-only clients could specify an arbitrary path for this argument, causing libvirtd to execute a crafted executable with its own privileges.

It was discovered that libvirtd, versions 4.x.x before 4.10.1 and 5.x.x before 5.4.1, would permit readonly clients to use the virDomainManagedSaveDefineXML() API, which would permit them to modify managed save state files. If a managed save had already been created by a privileged user, a local attacker could modify this file such that libvirtd would execute an arbitrary program when the domain was resumed.

Flatpak before 1.0.7, and 1.1.x and 1.2.x before 1.2.3, exposes /proc in the apply_extra script sandbox, which allows attackers to modify a host-side executable file.

The KVM implementation in the Linux kernel through 4.20.5 has a Use-after-Free.

In the Linux kernel before 4.20.8, kvm_ioctl_create_device in virt/kvm/kvm_main.c mishandles reference counting because of a race condition, leading to a use-after-free.

An issue was discovered in sd-bus in systemd 239. bus_process_object() in libsystemd/sd-bus/bus-objects.c allocates a variable-length stack buffer for temporarily storing the object path of incoming D-Bus messages. An unprivileged local user can exploit this by sending a specially crafted message to PID1, causing the stack pointer to jump over the stack guard pages into an unmapped memory region and trigger a denial of service (systemd PID1 crash and kernel panic).

In PolicyKit (aka polkit) 0.115, the "start time" protection mechanism can be bypassed because fork() is not atomic, and therefore authorization decisions are improperly cached. This is related to lack of uid checking in polkitbackend/polkitbackendinteractiveauthority.c.

In Artifex Ghostscript through 9.26, ephemeral or transient procedures can allow access to system operators, leading to remote code execution.

A vulnerability was found in mod_auth_mellon before v0.14.2. If Apache is configured as a reverse proxy and mod_auth_mellon is configured to only let through authenticated users (with the require valid-user directive), adding special HTTP headers that are normally used to start the special SAML ECP (non-browser based) can be used to bypass authentication.

A flaw was found in libssh2 before 1.8.1. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used as an index to copy memory causing in an out of bounds memory write error.

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way SSH_MSG_CHANNEL_REQUEST packets with an exit signal are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.

An integer overflow flaw, which could lead to an out of bounds write, was discovered in libssh2 before 1.8.1 in the way keyboard prompt requests are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.

It was found that the forceput operator could be extracted from the DefineResource method in ghostscript before 9.27. A specially crafted PostScript file could use this flaw in order to, for example, have access to the file system outside of the constrains imposed by -dSAFER.

It was found that the superexec operator was available in the internal dictionary in ghostscript before 9.27. A specially crafted PostScript file could use this flaw in order to, for example, have access to the file system outside of the constrains imposed by -dSAFER.

Openwsman, versions up to and including 2.6.9, are vulnerable to arbitrary file disclosure because the working directory of openwsmand daemon was set to root directory. A remote, unauthenticated attacker can exploit this vulnerability by sending a specially crafted HTTP request to openwsman server.