A linux security update has been released for Debian GNU/Linux 9 Extended LTS to address several vulnerabilities.
Package linux-5.10 Version 5.10.179-3~deb9u1 (stretch) Related CVEs CVE-2023-2156 CVE-2023-3390 CVE-2023-3610 CVE-2023-20593 CVE-2023-31248 CVE-2023-35001
Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks.
It was discovered that a flaw in the handling of the RPL protocol may allow an unauthenticated remote attacker to cause a denial of service if RPL is enabled (not by default in Debian).
A use-after-free flaw in the netfilter subsystem caused by incorrect error path handling may result in denial of service or privilege escalation.
A use-after-free flaw in the netfilter subsystem caused by incorrect refcount handling on the table and chain destroy path may result in denial of service or privilege escalation.
Tavis Ormandy discovered that under specific microarchitectural circumstances, a vector register in AMD "Zen 2" CPUs may not be written to 0 correctly. This flaw allows an attacker to leak sensitive information across concurrent processes, hyper threads and virtualized guests. For details please refer to <https://lock.cmpxchg8b.com/zenbleed.html> and <https://github.com/google/security-research/security/advisories/GHSA-v6wh-rxpg-cmm8>. This issue can also be mitigated by a microcode update through the amd64-microcode package or a system firmware (BIOS/UEFI) update. However, the initial microcode release by AMD only provides updates for second generation EPYC CPUs. Various Ryzen CPUs are also affected, but no updates are available yet.
Mingi Cho discovered a use-after-free flaw in the Netfilter nf_tables implementation when using nft_chain_lookup_byid, which may result in local privilege escalation for a user with the CAP_NET_ADMIN capability in any user or network namespace.
Tanguy DUBROCA discovered an out-of-bounds reads and write flaw in the Netfilter nf_tables implementation when processing an nft_byteorder expression, which may result in local privilege escalation for a user with the CAP_NET_ADMIN capability in any user or network namespace.
For Debian 9 stretch, these problems have been fixed in version 5.10.179-3~deb9u1.
We recommend that you upgrade your linux-5.10 packages.
Further information about Extended LTS security advisories can be found in the dedicated section of our website.