Off-by-one in Linux kernel - CVE-2020-27171
Published: March 29, 2021
Vulnerability identifier: #VU51775
CSH Severity: Low
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2020-27171
CWE-ID: CWE-193
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
The vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists due to an off-by-one error in kernel/bpf/verifier.c affecting out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations. A local user can run a specially crafted program to gain access to sensitive information on the system.
Remediation
Install updates from vendor's website.
External links
- http://www.openwall.com/lists/oss-security/2021/03/24/5
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.8
- https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/patch/?id=10d2bb2e6b1d8c4576c56a748f697dbeb8388899
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FB6LUXPEIRLZH32YXWZVEZAD4ZL6SDK2/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QRTPQE73ANG7D6M4L4PK5ZQDPO4Y2FVD/
- https://www.openwall.com/lists/oss-security/2021/03/19/3