Debian DLA-1232-1 : linux security update (Meltdown)
High Nessus Plugin ID 105622
SynopsisThe remote Debian host is missing a security update.
DescriptionSeveral vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks.
Multiple researchers have discovered a vulnerability in Intel processors, enabling an attacker controlling an unprivileged process to read memory from arbitrary addresses, including from the kernel and all other processes running on the system.
This specific attack has been named Meltdown and is addressed in the Linux kernel for the Intel x86-64 architecture by a patch set named Kernel Page Table Isolation, enforcing a near complete separation of the kernel and userspace address maps and preventing the attack.
This solution might have a performance impact, and can be disabled at boot time by passing `pti=off' to the kernel command line.
Andrey Konovalov reported that that USB core did not correctly handle some error conditions during initialisation. A physically present user with a specially designed USB device can use this to cause a denial of service (crash or memory corruption), or possibly for privilege escalation.
Dmitry Vyukov reported that the KVM implementation for x86 would over-read data from memory when emulating an MMIO write if the kvm_mmio tracepoint was enabled. A guest virtual machine might be able to use this to cause a denial of service (crash).
It was discovered that some implementations of the Salsa20 block cipher did not correctly handle zero-length input. A local user could use this to cause a denial of service (crash) or possibly have other security impact.
It was discovered that the HMAC implementation could be used with an underlying hash algorithm that requires a key, which was not intended.
A local user could use this to cause a denial of service (crash or memory corruption), or possibly for privilege escalation.
Eric Biggers discovered that the KEYS subsystem lacked a check for write permission when adding keys to a process's default keyring. A local user could use this to cause a denial of service or to obtain sensitive information.
For Debian 7 'Wheezy', these problems have been fixed in version 3.2.96-3.
We recommend that you upgrade your linux packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpgrade the affected packages.