Use-after-free in Linux kernel - CVE-2021-29657
Published: July 25, 2022
Vulnerability identifier: #VU65770
CSH Severity: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2021-29657
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
The vulnerability allows a remote user to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in arch/x86/kvm/svm/nested.c. An AMD KVM guest can bypass access control on host OS MSRs when there are nested guests and execute arbitrary code on the hypervisor.
Remediation
Install updates from vendor's website.
External links
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2177
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12
- http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html
- https://security.netapp.com/advisory/ntap-20210902-0008/