CVE-2023-0045 Incorrect indirect branch prediction barrier in the Linux Kernel
Attackers can bypass Spectre mitigations by exploiting a timing gap in the prctl syscall, potentially reading sensitive memory.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-0045?
CVE-2023-0045 is a medium-severity vulnerability in Debian Debian Linux, published on 25 Apr 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The current implementation of the prctl syscall does not issue an IBPB immediately during the syscall. The ib_prctl_set function updates the Thread Information Flags (TIFs) for the task and updates the SPEC_CTRL MSR on the function __speculation_ctrl_update, but the IBPB is only issued on the next schedule, when the TIF bits are checked. This leaves the victim vulnerable to values already injected on the BTB, prior to the prctl syscall. The patch that added the support for the conditional mitigation via prctl (ib_prctl_set) dates back to the kernel 4.9.176.
We recommend upgrading past commit a664ec9158eeddd75121d39c9a0758016097fa96
Weakness: CWE-610
Which versions are affected by CVE-2023-0045?
It affects 8 products.
Products include Debian Debian Linux, Linux kernel, Netapp Active Iq Unified Manager, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware and 2 more.
How do I fix CVE-2023-0045?
Apply the vendor's patch.
Is CVE-2023-0045 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-0045 exists.
Public exploit code: 2 proofs of concept on GitHub.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2023-0045, GHSA-9x5g-vmxf-4qj8, UBUNTU-CVE-2023-0045.